User blog comment:Lyndongwapo/New Game Mode:Mix Mash Champion/@comment-7481207-20150511192206

There is no need to actually do anything with animations. Dota's ability draft uses the hero's default animation of the same slot, so regardless of what ability is in the Q slot, it will use its Q animation. Sure, this looks weird (and sometimes hillarious), but it also means a lot less work that would need to be done for this game mode.

Also, Legends of Dota (a mod that is more similar to this than ability draft is), uses a system that bans certain combination of abilities (such as only allowing a single range increasing ability), which is a good solution to OP combos without needing a unique nerf for each kind of ability that breaks in multiples.