Specifically, this one:
It appears at roughly 1:03 in the Hollow Ataraxia track (immediately following the section that FGO uses as regular Saber Altria's NP BGM), and at 0:33 in the EXTRA track. NUMBER 201 don't normally seem to reuse motifs unless the tracks are related in some way, so I wondered if there's some connection I'm missing? (Even one as small as "the song appeared in promotional material back when they were trying to convince everyone Nero was actually Altria.")
