This is my build for Mordekaiser which focus on TT, please read the guide before voting, downvotes are welcome if they are explained in the comments, it would just be another troll vote otherwise.

Cons:

Morde has no escape mechanism.
He doesn´t have CC except for the CC items he uses.
He is constantly focused by CC and can die really fast if he is not using any abilities

Pros:

Great at farming.
Controlling lanes.
Can deal high amount of damage to both turrets and enemy champions after buying lich. Incredible survability while he is using his abilities.
Can turn enemy carries against their team with his ult.

Marks:

I get Greater Mark of Magic Penetration 8.5 (14 with quintessences) magic penetration early game can make a huge difference in the damage you deal, I wouldn't change this runes for anything

Seals:

I use Greater Seal of Ability Power but this can be changed for seals like Greater Seal of Vigor or Greater Seal of Vitality

Glyphs:

Cool down reduction seems to be the best choice here so I use Greater Glyph of Cooldown Reduction

Quintessences:

Here I use more magic pen runes for a total of 14 magic penetration, cd reduction quintessences are also viable

I think Ignite and Flash is a great spell choice for TT, ignite can be used with morde's ult for easy kills and flash can be used to gank or escape as I explain later in this guide

Alternatives

Ghost use this spell with haste to get 33% movement speed, but because there is a 30% speed buff in TT this may not be the best choice

Exhaust not highly recommended when playing against skilled players, but a well timed exhaust can always save you, or it can get you a kill

Cleanse this is a spell that should be considered, morde can easily be killed after being silenced/stunned when you are using an AP build

Clarity NO

Other than the spells I just mentioned above I don't think ap morde can find any other spells useful

Even tough morde doesn't have any skill that has CC he is really powerful, and can control a lane easily, it doesn't matter if it's mid on rift, or top on TT, this is because of his ability to harass using Siphon of Destruction to generate shield and deal damage to enemy champions, the sequence I use is r>e>w>q with the exception of leveling up q at level, 4 (having another ability available is always helpful) or you may level it up into level 13 or a little sooner depending on your needs.



Iron Man Morde's passive this is why morde is hard to lane against, you can try harassing enemy champions when its over 70% of its capacity.

siphon of Destruction As I said this is the main tool for morde lane control and farming, I always level up this ability if it's available, (it's not available at level 6 and it's already maxed at level 9) you can also use SoD to prevent ganks by using it on a brush before going in it also works if you are trying to find someone who is using a stealth skill.

Creeping Death Great for farming when used at a high level and ap, even before, it can be used as some sort of weak basic attack which deals AoE to nearby minions, using this on an ally minion can be very effective to leave enemy minions vulnerable for last hitting with SoD.

Mace of Spades This is an ability that imo is almost useless early game, because you don't want to get close enough to enemy champions at that point of the game, this is the last ability I max but this is my favorite skill for late game, specially after I get lich bane, when hitting single targets lich bane passive will be buffed by morde's q and its damage will be lower when hitting multiple targets, it has a low cd and it resets morde basic atack so you can use this when you are trying to destroy a turret as fast as you can.

Children of the Grave Morde's ult, my favorite ult in LoL, and not only because it's health regen potential or its damage, but because it has the potential of turning an enemy carry against his own team, using this wisely can win team fights, there are different ways of using it, using the ignite/ult combo for early kills, saving yourself using it with someone with a lot health, and my personal favorite, using it to obtain ghosts.

Ghosts

Depending on who you kill your ghost can be useful in different ways

Tanks: You can use them to dive a turret or kill powerful monsters as baron.

Casters: Can buff your own AP making you a bigger threat during its duration.

DPS: Can deal great damage to their own team champions and turrets, buff morde AD?, not very helpful usually but any stat is helpful, it can also increase mace of spades damage.

Countering morde's ult: There are certain champions and items that can prevent morde from using his ult against them:

Nocturne can use Shroud of Darkness to completely block morde's ult as well as Sivir with Spell Shield or just someone with Banshee's Veil, always look for this and try using other abilities against them before using Children of the Grave, this should prevent someone from blocking it and if you see someone is using Quicksilver Sash you should hold your ult into you are sure you can kill them immediately, they will probably use sach's active to prevent you from getting their ghost otherwise.

For morde I buy Regrowth Pendant and a Health Potion as first items, why?, because morde needs all the health regen he can get early game without affecting his late game, this item makes morde's abilities easier to spam, there are also other items that morde could use:

Amplifying Tome + Health Potion I would only recommend this if you are laning with a champion with a healing ability

Doran's Shield This option can be used if you like the extra hp and you are laning against strong ad champs

Doran's Ring Not very popular for morde, use this if you want to start with more health and ability power, like amplifying tome I would recommend this if you are laning with someone who can heal you constantly

Boots

I buy Sorcerer's Shoes for its 20 magic penetration, I wouldn't change this boots if you want to burst enemies' health, a more defensive choice would be Mercury's Treads, a great item when facing strong CC teams

Spell Vamp

This is the most important part of the build after buying boots I buy two spell vamp items.
Hextech Revolver, then I buy Sheen, and Will of the Ancients which is made from the hextech revolver I already bought, then I get another hex revolver for a total cost of 4500g, that means you will have 145ap, 40% spell vamp and the beginning of lich bane.

With 40% spell vamp and siphon of destruction doing 315 damage to minions (at level 5 with 150 ap) you will heal (126*minion)- 72 if you only hit one minion you will heal 54 health but hitting multiple minions, four for example, you will heal 432 health that's almost the same as Giant's Belt bonus health (430) and you can heal even more with higher ap or just by hitting more targets.

Mid/Late game

After stacking spell vamp you will need ap to make it work, I get Lich Bane which synergies with morde's q Mace of Spades, Lich bane will allow morde to kill almost any champion when fighting 1vs1 and will also deal a lot of damage to enemy turrets, then I sell regrowth pendant (if you haven´t do so already) and I get Rabadon's Deathcap for a nice 140ap and a passive essential for any strong caster, if the game continues further you can get an item of your choice depending on the games needs, for example:

Rylai's Crystal Scepter Always a great item for morde, this item can help solving morde's lack of CC and raising his survability and damage, I think of this item as a RoA made for morde

Deathfire Grasp Works great along with morde ultimate Children of the Grave and it has CDR something every ap morde requires, I would buy this item in case of facing enemy champions with high amounts of health and little magic resist

Void Staff After buying this item you would have 55% + 34 magic penetration, with this kind of magic pen morde could deal great amounts of damage even to a tank stacking mr and you will deal FULL damage to anyone with 75 mr or less


In the top of my head I can think of another 3 items like a hextech gunblade, mejai's soulstealer, or Zhonya's hourglass but as I said this item depends on morde's needs.

By the end of the game you can turn your hextech revolver into hextech gunblade and sell will of the ancient for another gunblade but this is not very likely to happen because the huge amount of gold you need to complete this build.

If things get a little tough and you are not doing so well (or your team fed) you can build a little more defensive:
for example in this game my teammates fed the enemy team, I had to stack mr and some armor to win the game

Alternatives early game items:

If you think spell vamp isn't very helpful and your early game is squishy you can replace it

Chain Vest This can be used to build many different items later in game, 45 armor is very effective early game and it's cheaper than most items

Negatron Cloak a version of Chain Vest for magic resist, and like chain vest this can be used to create a lot of items late game

It shouldn't be necessary to build tanky if you lane correctly, but in case you need to use this items for higher survability, I would buy at least one spell vamp item between or after buying those items.

PS I took the idea from building Negatron cloak and chain vest from Temzilla guide Mordekaiser: The Real Spell Vampire

Mid/late game section

Magic Resist

Abyssal Scepter I like this item because it helps Mordekaiser resistance and still gives him magic pen and ap

Force of Nature Not my favorite item to build when I'm trying to do serious damage but this item is cheaper than most of morde's items and it has a high amount of mr.

Quicksilver Sash If you are having trouble with CC you can buy this item for its active or Banshee's Veil for its passive

Armor

Thornmail If you are dealing with an ad carry you can try using this item, even though this would lower your damage

Frozen Heart It has a great cdr and a nice amount of armor, its aura can help you and your team in a team fight, I would recommend this item when you are not being focused

Zhonya's Hourglass It doesn't have that much armor but it does give you the advantage to keep your damage output high.

Other

Sunfire Cape I would only pick this item for champions who can stick long and close enough in a team fight to make its passive useful, not the best item for morde in my opinion and as for its farming capabilities morde is FINE without it

Spirit Visage I have seen this item in a couple of builds for morde, I would only recommend this for people who is new using morde, an experienced Mordekaiser shouldn't use this, yes it gives you a little hp mr and cdr but nothing worth of morde's item slot

Warmog's armor Morde should never buy items for just health I don't recommend this item by any means

Rod of Ages This is very similar to Rylai's Crystal Scepter, but RoA has a little more health and ability power after 10 minutes (310 health and 20 ap) of buying it, but it doesn't have Crystal Scepter passive, I wouldn't take this over crystal scepter

Note: the items above will increase morde survability but they will also lower its damage, the items morde should get depends almost completely in the game situation.

If you guessed right I didn't chose my items, masteries or runes randomly, in my point of view morde can be used successfully in two ways, full ap or tanky ap.

I choose to build mordekaiser full ap, instead of using FoN I stack spell vamp, this allows morde players to survive as long as they can deal damage, and like FoN it allows morde not to worry when using his abilities because it compensates for its health cost when damage is dealt.

As I said at my Introduction this build focuses on TT game play, you dont need high a amount of armor, mr or health, spell vamp should be the only thing you need to survive at team fights, this is why I focus on dealing damage, after I have bought WotA and hex revolver Lich Bane will make you a big threat to the enemy team, this item let you destoy turrets extremely fast without the need of buying any ad or as items.

at 0:16 and 0:24 you can see how lich bane does nuke damage to enemy champions and you can see how it works against turrets at 1:50


Rabadon's Deathcap My troll item if you wish to call it that way, it works for me and it works great along with my spell vamp and lich bane passive, this item can be changed for a more defensive option if needed, for example, Zhonya's Hourglass highly recommended to keep a high damage output and improve morde armor, or you can get Abyssal Mask when casters are the problem.

One of the greatest advantages morde has, is that he is great at farming, morde has a lot of AoE which gives him an advantage at farming over other champions, there is not much to say in this section except, farm safe into lvl 5, when morde can destroy almost anyone in lane, is easy to farm using creeping death on ally minions and using SoD afterwards to last hit, try to deal little amounts of damage to the enemy into level 6, then wait for him to be under 30% of his hp or when you think you can get a kill using Children of the Grave and Ignite combo, if you still have health after killing an enemy champion and there are no minions to kill on lane, you can move to a nearby minion camp for quick gold, or recall to get equipments and keep pushing lane, remember that morde is an easy target for a gank before he gets its spell vamp, placing wards on strategic positions may save your life

also, In TT morde can solo dragon as soon as he gets its 40% spell vamp

The green circles are the places you should ward while the blue circles are buffs, in twisted treeline dragon is the number one priority, after killing dragon you will receive 280g and a damage buff which depends on your champion level, if a team achieves to control dragon during the whole game its almost certain that they are going to win, during a TT game dragon will be available around 4 or 5 times(he has a 5 minute respawn time), that means during a normal game dragon can give you between 1120 and 1400 gold.

ad carries always hunt lizard this is why you need to ward him and because it is also the center of the map you can prevent ganks.

Playing morde on TT

In my opinion morde is not very effective in summoner rift but in TT he can easily carry, you don't have to worry about CC as much and is easier to win the game by yourself even if you have bad teammates, if you are going to use morde on TT try playing on the top lane and dont overextend unless you have warded.

Flash

You can use this spell as an escape mechanism or you can use it to gank, if you are laning top you can flash into dragon to escape but if you are laning bot you can always use it to flash from lizard into a brush in top and gank.

Buffs

Crest of Flowing Water: This is almost the same speed you get with ghost using it along haste, great for chasing or escaping (given by Ghast, 30% movement speed)

Crest of Nature's Fury: Even tough morde doesn't need attack speed the 10% cdr is very useful for him (given by Rabid Wolf)

Crest of Crushing Wrath: after killing Ebonmaw, the Terror of Zaun (twisted treeline dragon) you will get this damage buff to deal 1%*level more damage doing 18% at level 18 of course, it has a two minute duration, 2:36 with masteries.

When planning team fights morde can turn fights around by obtaining an enemy ghost, and he does a lot of AoE, and can burst enemies health with Mace of Spades, he can also give ally champion a little more defense using Creeping Death on them, because he has no CC (unless he gets Rylai's Crystal Scepter) he cant stop enemy champions from killing his allies beside killing them.

When you are playing morde on mid you need teammates who call constant mias anytime an enemy is missing, morde is very vulnerable to ganks early on game, and this can ruin his laning face, and it's necessary to play safe when the enemy team has a jungler.

You have to pay attention on who are you laning against before you decide how you are going to play

Hard to lane against:

Anivia Even if you push her on lane you cant kill her with your combo because of her passive, the best thing to do when laning against anivia is ignore her, farm the safest way you can into she is oom then you can push her.

Malzahar I find this champ hard to lane against, (maybe is just me) his silence is a big threat to morde, if you can't generate shield you will be an easy target.

Caitlyn Her range is longer than morde's Siphon of Destruction and she can use Piltover Peacemaker from a safe range to deal great damage to you over time without taking any risk.

Easy to kill:

Ashe Morde's shield can take most of the damage or the complete damage from ashe Volley, and she has little health so is easy to harass her.

Kog'Maw He does little damage and morde shield can easily resist most of his attacks early game, he can run oom very soon leaving him vulnerable to harassment

Twisted Fate he is very similar to Ashe and Kog'Maw, he can't deal real damage early, if he is harassed correctly he will be almost useless late game.

There are more examples of champions that can be either easy or hard to kill but the champions above are the greatest examples I could think of from my experience playing morde.

A great champion, powerful, fun to use, and can beat almost anyone in lane, morde can adapt to most situations, he can be a pusher and even a carry when fed.

THANK YOU for reading this guide I hope it was helpful, suggestion are very welcome on the comment section, I have played hundreds of games with Mordekaiser but it wasn't into now that I decided to go a little further by learning from other people suggestions and opinions, ty for your time.

This guide was edited thanks to Temzilla and jhoijhoi feedback.

Update: I changed ghost for flash in my summoner spells