Just events and stamp cards.

Anyway, yeah, all the black units are pretty nice. Sybilla isn't ranked among the best blacks by DMM veterans because her Skill Awakening is underwhelming and the Aigis equivalent of endgame content is unfavorable to magic damage but neither of those factors are relevant yet on Nutaku. She remains a good tool to have in your box, especially for young accounts that otherwise have a hard time punching through armor due to relying on a bunch of silvers.