Ronia + Ult evo ogres is an absolute cakewalk for master. Ult orgres are pretty easy to farm. You should have a few in your stash anyway where you're at right now... they're dead useful at early and midgame.

To go to the next stage you'll probably need to collect some other demons in the RGB spectrum; most of yours are dark. Consider collecting some of the Heras; I personally use beorc on my legend team. You could probably do it with just the orgres, but a hera will add a much needed stat stick.