Games for iphone like Heroes vs Monsters or Cursed treasure?

I want a tower defense game, or just a fighting game where you don't just continuously upgrade the towers, but you can pick what skill theyll have or what skill the hero will get upon leveling up, like an rpg.

Clash of clans I absolutely love it you do upgrade but it requires skill and time to get there, you can chat with ppl better than you and they can help you out, try it out