From now on:
The the XP is calculated as if the lower level character has beat the higher level character, then the sum of the XP won is multiply by 2, and split between both players in equals shares. Level up bonuses are actives but there are no battles points for each round and no KO bonus.
This should help you levelup your cards quickly, while reducing the problem of "bad players" :)
Finally like i said before, thanks for the No Battle points and KO bonus, people should play there for Leveling intentions only.
So now doesn't this new feature eradicate the HAH play then? Oh no I love playing with HAH players they are a nicer bunch.