
Exactly. Here it just so happened to be Alistar, but Alistar is not the thing here
You should know better than to trust death recap, that thing has always been bugged.
Alistar's Pulverize does 240+50% AP at max rank. In order for his Pulverize to do 837 damage he would need to have 1194 AP.
Alistar's Headbutt does 275+70 AP at max rank. In order for his Headbutt to do 523 damage he would need to have 354 AP.
That is assuming he is doing true damage to you (i.e. you don't have any Magic Resist.)
Obviously he can't have 354 AP and 1194 AP at the same time so that's already something fishy. Furthermore, we can see he only has 240 AP from items so it isn't possible for him to do that much damage with either of his abilities.
Rod of Ages 100 AP Lich Bane 80 AP Abyssal Scepter 60 AP Total 240 AP
In conclusion, the champion isn't broken, death recap just does a really crappy job (and always has) telling you what actually killed you.
Maybe Alistar used his abilities more than once Or maybe he was under Zeke's buff
He said a "single rotation" in the post title. If Alistar had Zeke's then that would have increases his AP to 284, still not enough to do the damage. Even if he had 3 fire dragons it still wouldn't have been enough AP. The simple answer is that death recap has always been broken and unreliable.
Not even a Lichbane auto added in there. lol.
How did he reach 3k hp with a single hp item?
Ali's base hp at the late levels is 2.4k, RoA at max stacks gives what? 600? So yeah its enough. OP is probably off by a little since they are 16 and not 18 but still its close enough.
So he does as much damage as one Caitlyn auto-attack?
That's not one rotation.
That new Death Recap sure looks shiny! I'm glad Riot reworked it into a very reliable source of trusty info to know why and how you died! http://ih1.redbubble.net/image.139973808.1307/flat,800x800,075,f.u3.jpg
http://s27.postimg.org/3ltimtlwv/2618670_0199714375_Kappa.png
Yet he has next to no armor or magic resist compared to other Tanks.