im always getting frustrated with people in my group that waste all their coins on strenghtening even tho its not worth it until you donate max coins everyday,dont bother much with strenghtening,prioritize stuff like bm and group first then see if you have enough for strenghten too
I get coins from 9tails,survival trial,lucky wheel,from arena shop too card flip(got 50k coins one from summoning lol) and events,facebook comunity share too,arena grade,and home that would be all the places you can get coins from oh and yeah coins trial,sry for long post^^