Arena update
Just a thought but a good way to spice up arenas may be to make a battlechip store instead of those useless battlechip crystals. Have the store sell gold, units and specific champions that have been available through the arena at different levels per cost e.g.
100k battlechips = 100k gold
250k battlechips = 250 units
1 million battlechip = 4 star champ of choice
2 million battlechip = 5 star champ of choice
4 million battlechip = 6 star champ of choice
6 million battlechip = 7 star champ of choice