From what I'm getting, Revenge mode should be the saving grace to make 1V2's bearable...but getting it after about 3 hits in a 1v1 is an absolutely horrible idea.
Recommended Change: Reduce the amount of revenge gain from the opponent you are locked onto. Keep revenge gains the same from other enemies.
The best way to fix this would be to add a proximity in which extra enemies unlock the ability to gain revenge, and even or extra allies lock the ability to gain revenge.
This way 1v1, 2v2, you get the idea, nobody can get revenge. 1v2, 2v3, 3v4, the lesser team can gain revenge, and the greater team can't.