There is a problem that bothers me, some people abuse the challenge feature. here's what happens:
- Some guy gets to arena 1
- Looses the round in arena 1
- Goes and challenges another player
- Whatever is the challenge outcome, on the next round he plays back on the arena 1 even thought he lost his last game on that same arena
makes it unplayable for players climbing up the ranks, not saying to remove the challenge but restrict it for players fighting in Arena 5 and above