Even though Deleb has been fixed, she almost completely defeated him (under my guidance :P).
He started complaining that she was overpowered, and we switched for the next battle.
He simply lost his horses and Cerberuses, lost almost all his troops, but still won. He had 7 demonesses and 1 devil left :O
Conclusion - does Deleb counter Vittorio? Just don't say that she counters everyone.
After all, she has been fixed.