Well, posting this thread here to let people know of AP amumu, which on my last game a certain nunu laughed on untill i got around 2x his kills with less than half his deaths, also happening to start teamfights mowing down my opponents to 50% or less of their hp leaving the cleanup job for my teammates or doing it myself.
First of all, dont come with the same old "zomg that cant work, amumu is tank!!!111shiftone!", because i tried quite a few matches with amumu AP oriented and others Tank oriented, and in both cases i managed well (save for a few times where game was lost before it even started with quitters/lame connections/feeders that die in the first minute of the game (literally)), but in the AP case, the results were overwhelmingly better, because i managed for my team fast kills, and when starting on teamfights i would always see my opponents being crushed because i mowed their hp down so hard that my team barelly had to use 3 skills to finish the ones that didnt hit the sack on the start.
Of course, i wont lie, you WONT have the same durability as an tank amumu, and if you mess up, you will be squished down considering you wont be a tank this time, but on the other hand if used properly, i cant immagine what will kill you.
so far im going for 0/21/9, because even though im not a tank build, having some defense can help my survivability, but 21/0/9 can work just as fine, both can work well, rest goes for your playstyle
-Marks: Magic penetration or ap per level (either work fine, but magic pen wont really be a problem for Amumu)
-Seals: Mana regen (its not particularly nice to rely on blue buff on the match, so the better your mana regen, the merrier)
-Glyphs:Ap per lvl
-Quints:Health per level (why not, lets make this baby more durable)
here is the nice part, your gear will be the same as any normal AP user, but the set up i go usually is:
first: ability power tome and a potion, the tome will be turned on a Rylai´s scepter or void staff (both items will b on the build, but what comes first deppends on the MR on the opposing side)
second: boots of speed to be turned into sorcerer shoes, after all, magic pen is never too much
third: Rylai or void, whatever you didnt turn your first tome into
forth: Rabadon deathcap (obvious item for any AP user)
fifth: here you can fit whatever you think will fit better for your suvivability/nuking power, it can be lichbane, or will of ancients, or zhonya hourglass (zhonya if not here will be on the 6th item), any of the 3 choices is useful for you, i prefer lichbane to do some good damage even on headbutt after i cast my first skill just to pile on damage, but if you looking for survivability fast, then any of the other 2 should do the trick.
sixth item: zhonya hourglass, for a simple "i bandage someone from the opposing mass, ult, then zhonya for not getting squished"..
This build should easily grant you 650 to700 AP, and then comes the question: "bah, but wont that be still somewhat basic for any AP user by end game?", indeed, some can get to the 900 house, and if you know how to, go for it, but your damage will already be overkill just from this, because bandages and your ult scale on a 1:1 ratio, in another words, this 700AP will be extra 700 dmg on both those skills, easily jumping to 1k dmg end game per skill.
the order i usually go is:
"But why max Bandage throw first?" Simply because since its one of your 2 skills with 1:1 ratio, it will be your most damaging skill of the pack on the start, while E is only useful for a follow up and farming (and for farming lvl3 already do a very decent job)
"What about Despair?" well, unlike the tank amumu, you wont be dancing around your target for killing it with despair, and with good AP you get extra 3 points on the % removed, so its not like not leveling it earlier will actually harm you, most often fight will be over by the time u use your second or third skill leaving despair for a finisher in case your target managed to barelly survive the initial rape.
Results on skill damage
-Bandage toss: around 1k damage (300 base + 700 AP)
-Despair: around 5,7%(2,7% base + 3 extra from AP build) damage per sec aside the solid magic one(which i cant remeber, i guess 24 or so, will get better data latter on on a test custom game).
-Tantrum: around 500 or almost it (170 base + 300 or more from ap, again need to check how much it was on a custom game latter)
-Curse of the sad mummy(ult): around 1050 dmg (350 base + 700 ap) and a very nice stun.
-Huge damage on squishies sometimes 2 shotting them
-Squishy since its no longer a tanker
-requires you to KNOW how to use the champ, no point in having a 1k dmg bandage toss if you cant use the skill properly and cant land a single one
- its gear IS expensive, so you must guarantee some kills with it for faster money
- with lack of runes it may b dependant on blue buff, for its mana will be sucked out pretty fast, and you dont want to be out of mana when a miracle worker survive all the dmg you will pile on him.
When you decide to run this build, TELL YOUR TEAM DURING CHAMP SELECTION that u will go ap oriented so they get someone to be tank in your place, otherwise they will see your amumu, think "oh so we have a tank" to then in the middle of the match start saying "dangit you were supposed to be the tank you basturd!!!!". Dont be intimidated by people who try to shove in your head that "a tank amumu is better" because a champion who can blow away over half of the hp bars of the enemy team and most likelly kill one or 2 of them while stunning the survivors is far better than the one who will only stun the enemy team and let the rest of the team bust their butts for dealing he remaining 70% of the hp bars as dmg. It is a very reliable build, but the cons can bite you back if you give them room for it.
will update here with better info as soon as i can, hopefully this will be of help to some players and open doors to a different sort of amumu.