So. . . 4(5) against one, huh. Nidhogg is definitely pumped for this. Can the spirit even get hurt, and why is he ducking up the necrotic energy? Even if he's the servant of Thanatos, pretty sure Nidhogg(thr Spirit inside, not the charcter) trumps him on a mythological power scale, as well as with his stronger connection to the realm of death. Nidhogg basically is damnation; as he is where dinners were sent to be devoured in Norse Mythology. 

Moving on, City will most likely suffer heavily in the coming fight, cause I don't see this ending before Nidhogg pulls out his True Form. Odds are really stacked against him. Oh well, half of Crocus is probably really even disable anyway.