Not Updated For Current Season
Threats to Mordekaiser with this build
+ Enormous damage throughout the game
+ Best sustain of any bottom lane carry
+ Highest attack damage of any champion
+ Can perma-slow entire teams with Rylai's Crystal Scepter
+ Fantastic pushing power
+ Provides magic damage from bottom lane
+ Ultimate can provide a 6th teammate
+ Incredibly satisfying moments of extreme power
+ Dragon Force is the single coolest ability in the entire game
+ Low mobility
+ Melee and without substantial long ranged poke or waveclear
+ Minimally useful for sieging and taking turrets, which is the primary job of outside of teamfights.
+ No inherent utility, and only has slows after buying Rylai's Crystal Scepter
+ Poor waveclear before getting items
+ Weak early game
+ Long base cooldowns, especially early on
+ Very poor base attack speed
Mordekaiser's passive, Iron Man, converts 25% of the damage that you deal (12.5% for minions) into a decaying shield. The shield's maximum value is 25% of your max health, but decays at a rate of 1.5% of your base health per second until reaching 25% of the max shield value. The shield will not decay if either (1) Mordekaiser has under 25% shield, or (2) Mordekaiser has gained shield in the last 1.5 seconds.
Iron Man defines Mordekaiser's kit. Rather than using mana, Mordekaiser spends health to cast abilities but gains a decaying shield in return. The trade-off rewards high damage builds as you will prevent more damage than you would have taken from health costs. In teamfights, if you are not bursted down, you often remain high on shields and thus can end fights with nearly full health despite taking enormous amounts of damage.
Properly maintaining your shield in lane is the difference between getting bullied out and completely ignoring all poke.
Mace of Spades
Mace of Spades is an auto-attack reset which applies bonus on-hit magic damage. The first two hits do a good amount of damage, and the third hit does an enormous amount of damage. Use this ability to help last hit in lane or to finish people off in all-ins. It is dangerous to get into melee range while building heavily into damage, so make sure to judge the risk against your shield strength and team follow up.
Note that Mace of Spades encourages attacking multiple times, but we do not build any attack speed. Further, Mordekaiser has an atrocious base attack speed. Rather than standing next to a target, you often want to kite between auto-attacks during the 1.66-1.21 (levels 1-18) second delay between his auto-attacks.
We take Mace of Spades third, and max it second.
Note that Mace of Spades is coded as a multi-hit ability, unlike nearly all on-hit damage. This has some unique implications:
Mace of Spades bonus damage contributes to Iron Man's shield.
Spell Vamp will restore health at 1/3 strength. Note that Spell Vamp normally does not work with on-hit magic damage.
Your empowered auto attacks apply Rylai's Crystal Scepter's slow.
Harvesters of Sorrow
Harvesters of Sorrow is Mordekaiser's most important ability. It has 3 parts: a passive, an active, and a reactivation active.
When you last hit minions and share experience, Mordekaiser gains 1/2 of the experience lost due to sharing. With a support in lane, you gain 82.6% of experience bounty rather than 65.2%, while your support gets 65.2%. Note that when sharing experience with at least one person, minions give 130.4% experience rather than 100%. This passive allows Mordekaiser to be competitive as a bottom lane carry against ADCs and makes up for some of the gold lost due to getting zoned as a melee champion. You should always hit 6 before your opponent - use the opportunity to all-in.
Target a friendly champion, champion ghost (from your ultimate), or minion. You both gain 75 movement speed when moving toward one another. There will be a circle around each of you; as long as any part of these circles overlap, you will do damage over time to everyone in the area of either circle. The area is particularly large, so you can cover the entire width of a lane, an entire wave of farm, or most of a teamfight. Melee and ranged minions have reduced area on their zone, so you will have to get much closer to them in order to do damage. If you are with a melee support, you can both move into the wave with Harvesters of Sorrow active to quickly push into tower.
Since Harvesters of Sorrow is an AoE DoT, Rylai's Crystal Scepter and Deathfire Touch are extremely useful. Given its large area, you can potentially slow and damage 3-4 enemies for the whole duration. In teamfights, you usually want to target your frontline tank. With the bonus movement speed, you can follow up on engages. With the Rylai's Crystal Scepter slow, you and your tanks will easily be able to stick to targets and prevent any escape.
After it's 4 second duration is over, the minion it's on dies, or you reactivate it, Harvesters of Sorrow damages everyone in its area and heals you and your partner if it damages a target. This heal is reduced on minions. Even with a reduced heal, the reactivation actually grants significantly more health than the cost of the ability. With careful use and some ability power, you can completely negate the costs of all of your abilities. You do not need to have overlap to reactivate. Note that you can target yourself with Harvester of Sorrow with no nearby targets and still use the reactivation.
Use the reactivation to last hit minions, deal a bit of extra damage before an enemy runs out of the zone, or to get a small burst of health. If you still need the damage over time, do not reactivate.
A clever trick you can do is target a melee minion while the enemy wave dies. It will charge forward to the enemy. Reactivating will deal your opponent damage from long range.
We take Harvesters of Sorrow first, and we max it first.
Siphon of Destruction
Siphon of Destruction fills out our spell rotation and provides additional poke and sustain in lane. Siphon of Destruction does instant damage in a cone and restores a percentage of your max shield for each enemy champion it, in addition to the damage to shield conversion from Iron Man. Use this ability to harass lane opponents, last hit ranged minions, and deal damage in teamfights. The range on Siphon of Destruction is longer than the average ranged auto-attack, so you can trade as long as the cooldown is up. Hitting first means your opponent only hits shield, and is almost always a good trade.
Do not ever max E first. I see many guides suggest this, and it is never a good idea.
The base damage increases are small per rank.
The health cost increases are large per rank.
Siphon of Destruction has a 60% AD ratio. Given that Mordekaiser has the best AD in the game, the damage scaling per level is high.
Cooldown goes down negligibly per rank, while other abilities go down significantly.
As a result, you can actually lose more health from maxing E than by keeping it at rank 1. Additionally, without lower cooldowns on Q and W, you lack the ability to fight effectively. There are some rare cases where getting rank 2 early is useful, such as to help long range last hitting against oppressive zoning. Anything beyond that will hurt you.
We take Siphon of Destruction second, and we max it last.
Children of the Grave
Mordekaiser's ultimate, Children of the Grave, deals a small burst of percent max health damage followed up by a large amount of percent max health damage over 10 seconds, and heals you for the damage dealt. If the target dies while under the effects of Children of the Grave, you gain a ghost of the champion killed that you can control. All passives and on-hit effects of the champion work normally. You can target your ghost with Harvesters of Sorrow like a friendly champion.
This is the longest damage over time ability in the game, and our build capitalizes on it. Rylai's Crystal Scepter turns Children of the Grave into an 11 second slow, and Deathfire Touch adds a 68.75% AP ratio over the duration. Once you tag a target with your ultimate, they will not be getting away.
As a result of your increased experience gain, you will hit 6 before your lane opponent. Use this advantage and all-in with Children of the Grave. A full rotation coupled with some crowd control from a support should 100-0 any ADC.
Controlling the ghost takes practice. Make sure to micromanage your ghost as you would your champion. This means avoiding turret aggro (or intentionally taking it), target selection, and harassing opponents. Marksmen and Juggernauts are fantastic ghosts to have: Marksmen will take objectives for you quickly, and Juggernauts will facetank turrets, Dragon, and Baron as well as tank in fights. Note that your ghost's autoattacks will apply Rylai's Crystal Scepter's slow.
Passives still work for your ghosts, abilities like Silver Bolts and Bear Stance will still trigger. The ghosts are treated as a champion for purposes of all abilities. As a result, they can be affected by Wish, Requiem, Infinite Duress, and many other abilities that only target champions. You can use this fact to block Ace in the Hole and Enchanted Crystal Arrow.
We take Children of the Grave at 6, 11, and 16.
There's also a passive on Mordekaiser's ultimate. If you damage the Dragon and your team takes it, then you get a ghost Dragon. Yes, the actual Dragon. As long as you have an enslaved Dragon, you are the strongest person in the game. Dragon has unlimited leash range, enormous health, high damage as well as percent health damage, and applies Rylai's Crystal Scepter on-hit. Use Dragon to win teamfights, take turrets, or even solo Baron. With effective micro-management, Dragon will solo kill enemies or turrets and zone heavily in teamfights or sieges.
In sieges, you often get more value from harassing the enemies defending the turret than actually hitting with the Dragon, but this varies greatly from situation to situation.
Note that duration, attack range, and movement speed rank with rank. It takes practice to get objectives with the short duration on rank 1. At ranks 2 and 3, you can easily force down any objective in the game with time to spare.
I cannot emphasize enough that Dragon Force is the most powerful ability in League. You can 1v2 under an enemy turret. You can win teamfights 3v5. You can win games with no enemy turrets down and no Marksmen on your team in one push after level 11. If you are playing Mordekaiser, Dragon is the most important objective in the game.
There are two caveats to Dragon Force: (1) Any ghost you already have is killed upon gaining the ghost Dragon, and (2) You cannot cast Children of the Grave while controlling a ghost. That being said, the Dragon is always worth this cost.
Mordekaiser occupies a unique space as the only melee carry explicitly designed for a solo lane. I hope that you have enjoyed learning a lot about this special champion. Whether you are interested in trying Mordekaiser for the first time or want to get better at him, you should now have the knowledge to succeed in any matchup. Good luck and win every match!