Just a super brief guide on how to easily get to Darkness 15.
- Pick Diamond + Shotgun (Diamond gets big bonuses when she heals and loses hp)
- Focus on getting Reaper Rounds, Fusillade, the fire tree upgrade that lets you heal, and projectile speed upgrades. Speed makes your bullets travel faster, effectively increasing your reach.
- If you can get frost tree upgrades, go for them. They are absolutely broken with any weapon.
- Pick Spark + SMG and max Lightning Tree + Projectiles + Frost tree.
- Really any build that has frost in it. It just solos the game.