You goal is to spread heat so that your Deathcube Prime will proc [Energy Generator]. Damage does not matter: just mod for status heat and Fire Rate. Use [Contagious Bond] for status spread. Multishot for as many shots as possible. You will have more energy orbs than you know what to do with. The Riven helps but is not needed for this to work. Punch thru for added heat procs when dealing with hordes of enemies.

update 2025: a solely cold version of the above with [Shivering Contagion] mod works really well to proc the [Energy Generator] mod for [Dethcube].