Alliance Masteries
Now that war seasons are part of the contest, I think it's time we see something like "Alliance Masteries"
These would be separate masteries than your individual masteries that could either be earned by hitting milestones as an alliance or by donating personal mastery points to the alliance treasury (which would be refunded if you got kicked or left)
Nothing too crazy, but off the top of my head I was thinking:
1. Attack
1st pt - 1% 5th - 5%
2. Regen
1st pt - 0.5%/s 5th - 2.5%/s
3. Diversity
1st pt - 0.2% champion boost for each unique defender in war
5th pt - 1% champion boost for each unique defender in war
Thoughts? Others?