Hearthpwn

She requires very specific lobbies, with mechs and quilboars are the mere must, with dragons highly recommended. Cyclone is fine, but dragons are generally better, especially since those lobbies are Pyrospawn's wet dream. Not an easy hero to first with, very easy to top 2-3 though with those 3 tribes. 

I wouldn't waste time on grease bot, unless you need a filler or manage to get a pair into a triple. Much like Kali, you need multiples. Aggem isn't really needed, I'm barely out of tt3 before it's top5.

In a beast lobby you want a Brute, which you can Necrolyte its stats onto Hydra, and it's a 3, so it'd be e.g. a 7/11 even after you shift 16 gems from it. On nonbeast if I get a brute, I go to 5 earlier to triple into Foe Reaper, with the other options being mainly Macareal. 

C'thun being a viable hero is a sad joke, the buddy is plain awful, just compare it to Mukla's, who gets his buddy top of turn 5, and is generally better than AFK, even in the same lobbies.