https://forums.warframe.com/topic/1280720-nidus-prime-weapon-mutation-idea/

All is explained in the link above! I really think they could've done Nidus Prime better, Don't you agree?

A feature that works well with who he is, his place in the lore and gives more to look forward to when using weaponry that isn't often used! I'd like to see the devs at DE put a little more effort in to make Nidus prime go from a good improvement to a flawless one!