>>534685774
I think that would be too specific to justify being one of the 3 card types.
The most impactful and realistic changes I can think of, would be Quick somehow allowing NPs and Extra attacks to crit.

Agravain and Camazotz are the only anni servants I would have a positive reaction for.
I would also accept Daedalus or Columbus (Lily), but they just don't fit the bill for bein an anni servant.