User blog comment:Sifter66/What makes a late-game champion?/@comment-1920550-20150602002210

Late game comes in many flavours and forms. Kog'Maw is a unique example of a late game champion as both AD (due to his synergy with attack speed, crit, Trinity Force and W, allowing him to pump insane DPS from a long range) and as AP (high burst, low cooldowns, very long poke and insane waveclear).

Ashe is a lategame champion, due to not only her potent DPS from her passive and Q, but also her general range, W poke, the utility of her E vision and her ult CC.

Vayne due to being a hypercarry duelist. Caitlyn has a very under-rated lategame due to her range, natural attack speed and how her passive scales super well with levels and items.

Also certain tanks fit the description. Rammus scales very well into lategame due to his passive-W-Thornmail interaction and his ultimate, which makes him an insane tank, while giving him good DPS. Sejuani scales into lategame due to her tankiness, damage and her ult CC.

Various factors contribute to this, damage being a major one, but others such as utility, tank stats, range, cooldowns.