Originally Posted by LostInBoston
if amumu or malphite happens to get an early lead, they will finish the tank items they need so fast that they can start building damage. I have seen time and time again how high amumu AP ratio's are, his ultimate is hard to beat or even escape in any situation if he has liandry's, rylais, deathcap and sunfire cape. I really love playing amumu, but i will be the first to say that something about that situation needs to be tweaked. Amumu is not balanced. Even if amumu doesnt get an early lead. he can just keep farming and once his ultimate is lvl 3, it will ALWAYS win teamfights unless he and his team are ridiculously outclassed.
Amumu and Malphite aren't really proper representatives of Tanks as a whole, as they're more or less the best ones in the game - so they'll generally put any mage that isn't Karthus, Oriana, or Anivia to shame by comparison.
Beyond that anyone with AP ratios at all and an end-game build with plenty of AP will beat you to a bloody pulp and prevent you from escaping, the fact tanks can do it isn't terribly surprising. That's the reason gold remains incredibly relevant in the outcome of LoL, and the reason getting an early lead can cause you to snowball out of control throughout the rest of a game - which should cause you to win fights, and is something that can be said of every champion. So the fact 4 items allow Amumu to do that isn't impressive or unusual in any way. Amumu's a really strong pick more because he can win team fights through the utility and potency of his abilities alone without any items at all, which is the category most champions with a heavy focus on side-effects over flat damage tend to fall into. Amumu has a stun, gap-closer, AoE stun, free damage reduction, and %max health damage to remain relevant even when other champions would be shut down.