Draft Arena mode should be available 24 hours a day. Don't keep it time-limited please.

Many players are busy irl during the available hours, due to every day schedules, work, school, etc. 

This mode is really fun and creative, and it should be enjoyed whenever the player wants to.

 P.S. Also, there are no rewards for playing (apart from the "Draft Day!" event). Maybe a weekly rewarding system would sufice, based on winning drafts. Missions would be fun too (like, win while using a team of 4 bruisers).