Not Updated For Current Season
First off this is my version of http://www.mobafire.com/league-of-legends/build/morde-cooldown-reduction-never-hurt-so-much-12687, Most of the credit to this build goes to the creator of that one, However Once i got the revive on that build, my mordekaiser started falling apart. So thats why i made this variant.
I go 9/21 (9 in offense for magic pen and CDR) and 21 in Defense to become more unkillable.
however this is up to you, but 9/21 has worked out best for me, Your mileage may vary.
Revive and omen is youre core in this build (For the CDR, Active's, and Armor) You should always get this items first. but there a few different ways to build Morde, Ill list them below
Is the enemy team Ap Heavy? Go: Regrowth & Hp Pot -> Kindlegem -> Boots of swiftness -> HoG -> Omen -> Revive -> Banshees -> FaN -> GA
Is the enemy AD Heavy? Go: Regrowth & Hp Pot -> Kindlegem -> Boots of swiftness -> HoG -> Omen -> Revive -> Thornmail -> GA -> Frozen Mallet
Is the enemy team a mix? go with the build up top.
Do you want to do more damage? Follow the linked build in the intro.
If you dont have the CDR runes, Grab the CDR boots instead of BoS. And get ghost instead of tele.
Mordekaiser has a great early game, (Unless hes up against 2 ranged) use this to your advantage and dont be afraid to harass, your sheild should cover you.
You may have low cooldowns, But dont burst with morde, Instead use his spells to keep the sheild on.
If youre up against 2 ranged, max Siphon first, itll make harassing easier.
Use CoG and ignite together on Squishes on teamfights, itll make killing them easier, or make them back off and give you 5v4 advantage.
Use CoG on Ad champions.
REMEMBER TO POP YOUR ITEM ACTIVES!
With this build, youre not a main tank, or a DPS, You're a hard to kill. It does make you a tad more usless to your team, however you wont hardly ever die, and that gives them less gold, And makes you always there for the fight, Dont be afraid to tele to defend a turret against 1-3 people, If they dive, Pop CoG and ignite on the squishiest and try and kill him, This should make it a 2v2 or a 2v1, with you holding all the cards. But dont chase if they run to far away from the turret, the rest of there team could be on there way and thatll kill you.
be sure to comment, and tell me why this build sucks before you downvote so i can tweak it.