I thought morde was the bulky ap carry?
- Most of the time, he is. When that fits the team comp: http://www.mobafire.com/league-of-legends/build/mordekaiser-guide-tanky-ap-75694

Some of the time however, you want to play mordekaiser (because he's amazing and i'll explain shortly) and your team needs CC.

This build can be powerful, given your team can deal damage. I only suggest using this build in a 5 man.

Here's why:

We've all been in a teamfight that goes well for us but we still don't get a great push after the win.

Situation 1:
- the 5v5 breaks out and you kill 3, they kill 2.
It is now 3v2 in your favor and the other two started fleeing when they saw it was over. You chase and chase but you just can't catch them. You wish anivia was on your team for the wall, or if he is on your team, you wish he was close enough to wall.
A number of different wishes can go through your mind.

None the less, the 2 make it to their inhib tower. You 3 (half healthed) charge up and realize, you can't take the tower + inhib because the tower + 2 of them is just enough to stop you.
Even if you tower dive and kill 2, they might kill 1 or 2. Now you have 1 or 2 super low healthed champions and you can't stay long enough to put out the damage and safely get tower + inhib.
The situation SUCKS.

It would never have occurred if you were CC mordekaiser.

Situation 2:
- As those 2 run, you pop ghost and W yourself. If they are too far, you E them and permaslow them into oblivion.
- If you have a ghost, he can get the other.
- If you are fast enough, you can run past one, slowing him just enough with your W to allow your allies to catch him, catch the second one, and E -> permaslow him into oblivion.
- A number of combinations could have happened. As the teamfight ended originally, you could have popped randuin's on the runners and halted their retreat instantly.

Changing situation 1 into situation 2 can be a GAME CHANGER.

Late game: that could be the push to win.

Mid game: that could be an inhib to turn the tides of battle (super minions). Or it could be a free opportunity to drag uncontested for 190 global gold.

No matter what, just turning that into an ace yields more gold and global gold (to the dead allies) at least 150 for just a tower.

Failing to change situation 1 to 2 could be the seal of your defeat.
If their team was outdoing you all game and you managed good position and luckily got 3 of them (they attmepted baron, number of reasons to get the temporary turn around) then NOW is your chance to change the game. If you wound up with the 3v2 stalemate at a tower, you may have just wasted your chance. Sure you got 1 more kill, but who knows if luck will come again? Your chance at a comeback is now OVER.

Now I will explain the build + strategy step by step.

Mordekaiser has no inherent CC and therefore, I chose the most CC in items you can get while maintaining a tank build.

The double up on rylai's and frozen mallet goes somewhat like this.
E -> 15% slow -> melee -> 40% slow -> permaslow -> death.

The constant CC will help you stop carries from escaping, save allied carries, slow down the enemy's ability to focus and kite.

Your core items for the CC:
Frozen Mallet + Rylai's

Bonus utility + teamfight utility:
Randuin's

Alright so into the build order.

Regrowth pendants for laning to cancel out the costs of your moves.
Boots to avoid possible ganks/skillshots.
Negatron to tank out harass better.
Giants belt next b/c morde has low health and scaling.
Chain vest to finish off your magres/arm/health tankiness.
Finish force of nature because you have all the items building in and it gives you nice bonus movespeed.
Immediately go into frozen mallet b/c by this time you need the good 40% CC (better than rylai's because i assume you can hit them once to start the permastun).
Then go with randuin's to help the teamfight effort by aoe slow (can also be used if you stumble upon one of them kited).
Finish up by getting that rylai's.. Now your CC is complete.
Lastly throw in that guardian's for the extra arm/magres + revive.

This build w/ masteries/runes/items will have
Health: 3411
Health per 5: 82.35
Armor: 203.7 (randuin's nerf)
Magres: 205.2
Magpen: 14.22 and 15% (mastery)
AP: 80

Frozen mallet, why get it at all?
- morde cannot rely on rylai's to do all the slow for him considering he doesn't get to utilize the 35% slow (all skills are dots or aoe).
- allows you to permaslow
- fat health on the item

Rylai's, why get it at all?
- this item starts the permaslow combination and can make your slow AOE considering your moves are AOE and you cant AOE melee everyone.
- nice health
- nice ap

Randuin's, why get it at all?
- in the teamfight you get a massive aoe slow and attack speed reduction.
- in this build, the slow on randuin's will last 4 seconds (that's a lot in a teamfight!)

WHY IONIAN BOOTS YOU NOOB?
So you think sorc pen is better eh?
1 - the cooldown reduction yields more dps (functions as atk speed for casters) and the proof is in "Items: why this and not that?" on this build: http://www.mobafire.com/league-of-legends/build/mordekaiser-for-ranked-72244
2 - the faster you can cast your moves, the longer you can keep people slowed by 15% if you cannot melee them (say you are in a teamfight).

Why force of nature?
- gives just enough movespeed to compete
- most magres on any one item
- gives great health per 5 on a health costing champion
- you need the items that build into it

Why Guardian angels?
1) all good tanks need 200+arm/magres and 3k+ health. This build achieves that and incorporates all the CC utility but only because guardian's angels is combined with just the right combination of runes to meet those requirements.
2) without it, either arm or mag res wouldn't meet the requirements.

1) you can CC greatly in a teamfight with the maximum randuin's, aoe slow from rylai's + moves and you can permaslow with frozen mallet.
2) you can sustain heavy amounts of damage because you meet the requirements of a good tank.
3) you did sacrifice AP for CC... but...
- most ranged carries will have 80 magres (30 base + banshee's 50)
- most melee dpsers will have around 105 magres (30 base + banshee's 50 + merc treads 25)
- most ap carries will have around 137 (base 30 + banshee's 50 + abyssal 57)
Bear in mind that they may vary because some champs scale in mag res.
This means:
say you have 300 AP, your E will do: 405 base. Say you run sorc shoes and have 30 magpen, or even 50 b/c of abyssal with the 15% pen.
This will hit the:
- ranged carry for 322 (rounded down)
- the melee dpser for 276 (rounded down)
- the ap carry for 233 (rounded down)
With the CC build you will (with base 273) hit the:
- ranged carry for 174 (rounded down)
- the melee dpser for 154 (rounded down)
- the ap carry for 133 (rounded down)
1) You deal out this damage 20% faster than the higher damage. (however still less damage unless you fight for a very very long time).
2) You sacrificed in order to make sure those champions do not get away.

The major reason it DOESN'T matter:
- mordekaiser was never crazy because he could eat teams apart with his Q W E. Mordekaiser was crazy because he could STEAL the enemy carry and use them to sustain himself and tear the enemy apart.
The massive CC greatly increases your team's chance of taking out the enemy carry, ensuring you can ult -> steal them.
Even though you have little ap, your stolen carry will just as easily tear down the enemy team. To top it off, The carry you stole (hopefully ranged) will get your Frozen Mallet slow. That's right.
Get the enemy carry and there is NO escape.
Even if you got a dpser, you can easily E an enemy for the 15% slow, and watch as your dps ghost permaslows them.
If you are really skilled, you can attack one enemy (permaslowing them) and have the ghost attack another enemy (permaslowing them).
Now both of them are open to be eaten by your team (if your ghost doesn't do it faster).