ditch corrupt light and savagery asap, switch to supreme cannon + desolation instead. The final build uses recoiler though, but alternatively, a hammer + repulsor will suffice as a substitute. If you happen to get a dawnblaze in that span of time, try and build towards dawnblaze + flaminator, which bullies low ranks due to the amount of corrupt light spammers there are. You should also ditch nightmare as a heat torso once you get windigo or molten plasma vest, the former being a poor man's version of the latter being the most overpowered torso in the game.
I have zero heat drones and i had no luck on getting magma recoiler, so i just used terror cry and, more recently, the flaming hammer for knockback. But I've been stuck like this for way too long, what do you think i should do with my mech?