Cantare return on reload takes damage mods properly now... time to party!
Build Specifics
Galvanized Diffusion - Mandatory Multishot
Galvanized Shot - More damage with priming
Lethal Torrent - Fire rate + more Multishot
Synth Charge applies to every single returning dagger
Primed Expel mod for more damage, if you don't own Primed Expels use Pistol Elementalist for more damage over time from slash procs or non-primed Expel for more raw damage
No CC mod because [Cantare] passive sets crit to 300% exactly when the daggers return on reload
Elements
Pure corrosive for more raw damage, should work against Grineer and Murmur (replace [Frostbite] with [Jolt] or [Primed Convulsion])
Pure toxin for Corpus (replace [Frostbite] with [Pathogen Rounds])