Extreme Demon Dilemma

Hi everyone.

So I've been stuck with Leyak as my hardest for the past 2 years and I genuinely cannot progress into extremes. I've been playing Acu on and off since beating Leyak and the best run I got was 77%, dropped it today by the way cuz the level sucks.

So, what are some good starter extremes? Preferably for mobile so please no Cataclysm or Bloodbath or whatever.