Game mode that offers the ability to choose a champ in queue...
Even if it's bots... cause it's just wildly frustrating to try to beat 4 people to the punch line of the new champ you want to practice.
Yeah... a custom game... but that's a bit lame, doesn't really let you figure out combos and such in the same way.
Posted in behavior cause this post is prompted by extreme negative behavior and it could help alleviate it.