AM I THE ONLY ONE? having a bug that i can't remove the last card from my deck? i have a sky watcher in my deck and i can't remove it...have this problem since a few weeks.
archer, warrior, healer combination is enough to clear all quests. for 14 and 15 it's important to split your squads appropriately and advance them in the correct order to the towers to destroy them. i usually start with a squad of 3 warriors 4 archers and 3 healer.
to escape choose the middle door in the end and lure the dragon(?) to the trap and after triggering it duck and the trap will kill the dragon. go back after the dragon is killed and then exit through the right door.
for the annoying ninja champions save enough mana to crush them with meteors. otherwise try to freeze them with the crypts or with the banshee tower disable their hiding skill.
i think it's hard to keep the first one and the third one. for the second one you sometimes check if it's ok. and for the fourth one you keep holding your spacebar and check it sometimes and release the spacebar when seeing something coming from the upper part.