Introduction
So you think Mordekaiser is one beefy tank? Maybe, but I never thought of him that way. I've been using the Master of Metal for a while now, but tanking just never suited my style. I've used him in many, many ways: Tank Morde, Hybrid Morde, even AD Morde. In this guide, I'm going to show you how to build a successful AP Mordekaiser without having to suffer from the harmful effects of his HP-draining skills.
Pros / Cons
PROS:
-By mid game you dish out a lot of damage
-Easy to farm
-Difficult to be harassed due to shields
-Great laner
CONS:
-Everyone eats you by end game
-You are unable to put up shields early game
-Skills will eat up your life if you can't get spellvamp early
Masteries
Firstly, nine in offense is for cool-down reduction, ability power, and spell penetration. Believe it or not, it can be quite useful. Twenty-one in utility is for even more cooldown reduction, and on your summoner spells too. The reason there are two points into the duration of monster buffs is because I had no where else to put them. You could put it into ghost if you chose to use the summoner spell.
Skill Sequence
Basically, all you have to do is learn all your abilities once, and get your ult as soon as possible. The skill you want to prioritize is 
since this is your main farming/harassing ability.
Items
To fix Mordekaisers HP problems, most would get health regeneration, but as I keep saying, THIS IS NOT A TANKING BUILD. Spellvamp is the way to go, but, most people don't know what spell vamp is. Spell vamp is just like life steal but for abilities.
Doran's Shield
10 Armor, 120 Health, 8 Health per 5 Sec.
Most people choose to start with a Regrowth Pendant, but I find a Doran's Shield more useful because it gives more health. Also, your going to have to sell it soon so why not pick the item that gives you more benefits.
Sorcerer's Shoes
20 Magic Penetration. UNIQUE Passive: Enhanced Movement 2.
This item is crucial to most mages although if you wish to replace it with Mercury Treads, its your choice
Will of the Ancients
+50 Ability Power UNIQUE Aura: Gives nearby allied champions +30 Ability Power and 25% Spell Vamp.
The aura will support the mages on your team as well as give you spell vamp at the same time. The aura also stacks so its best to lane with champions who will most likely get this item such as: Vladimir, Swain, and other AP champs.
Hextech Gunblade
+60 Attack Damage +75 Ability Power +20% Life Steal +25% Spell Vamp UNIQUE Active: Deals 300 magic damage and slows the target champion by 50% for 3 seconds (700 range). 60 second cooldown.
This item gives you a huge variety of effects; I'm only interested in the spell vamp and AP. Although, the Active ability can slow your opponents, which can help you when you're chasing. The attack damage can also increase the amount of power on your 
but the lifesteal is utterly useless.
Rabadon's Deathcap
+140 Ability Power UNIQUE Passive: Increases Ability Power by 30%.
You're a mage, so obviously you would need this. It gives an immense amount of AP and the UNIQUE Passive makes it even more so.
Guardian Angel
+68 Armor +38 Magic Resistance UNIQUE Passive: Revives your Champion upon death, restoring 750 Health and 375 Mana. This effect can only occur once every 5 minutes. If your getting focused in team fights, you don't run. You're just too slow to be able to escape the brawl alive. You don't fray from a fight either, reviving is the answer.
Build Guide
Discussion (4)
You need a way to handle tanks in your lane, so I picked these runes, you will definitely see the difference late game.
This isn't a tank set, but you don't want to be a squishy Morde do you? This will cover your blind spot.
It won't help early in game, but it will help mid-late game giving you 27 ability power at lv. 18.
The movement speed doesn't seem like much but it helps at times. Whether your trying to escape a gank, or just trying to harass a bit more.
More magic penetration.
Ghost is an alternative spell for Mordekaiser. You can chase down enemy champs or run away.
Exhaust is pretty good, used for chasing or running but its just not for Mordekaiser.
Cleanse is a maybe, I'm not sure how useful this can be since the cooldown is pretty long.
Revive is the reason you're dying.
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