Since (8 Iron Bullets) + (1 Blaze Powder) = (8 Blaze Bullets),

(8 Iron Bullets) + (1 Blizz Powder) = (8 Blizz Bullets)
Similar for Blitz and Basalz powders

Blizz bullets slow enemies down, obviously
Blitz bullets summons lightning where landed
Basalz bullets have large knockback

Mod compat will be kept to a separate mod. I'll note these down as candidates though.