My change proposals:
1. New rewards for every battle - I didnt really take this event too seriously, so I just auto battled my way up to tier 17 and said, screw those two orbs. Today I went up to tier 18 - wow, I thought each battle will start at tier 1 with fresh rewards - means I can safely auto battle until I reach tier 20 - THATS PRETTY LAME IMO.
2. I generally dislike Rival Domains because of units respawning - perma death is needed here.
3. As far as the actual game mode is concerned - I think I hate it - cant really get into it. They should build an arena mode around it - with perma death etc.