Hi,
just a suggestion for the zombie dmg challenge in eu1:
the required dmg for each rank should be lowered, for rank 4 you need to deal 1600 dmg (as zombie) is quite high. I checked the stats of some higher levle players and most of them are stuck at level 4 or 5 while they have many other challnges on higher levels.
Maybe 100 dmg per rank would be more realistic but 400 is quite much as zombie 