There is no power race anywhere is the game, unlike pocket fantasy. The only "power race" is the arena (it's a bit logical) and it's 100% avoidable if you don't like it. No exclusive character or whatever.
But yeah, I like the current version a lot. Both the chinese version and the Japanese one had things which made me worry (The fact max stars were different depending of the starting star of character in chinese version, the fact you had no free draw in japanese one), but the Nutaku version is curiously really, really fair on that.
Anyway, pro tips: Don't waste time on reroll, the current 3* will be quickly outclassed by the 1*. By the way, don't waste too much ressources on 2* either. 3* are good for the first months, but Trisha, Naladia and Elnora will be everyone core for a long time.