Damien Wayne vs Kid Cass
Who would in a fight, Damien as we know him at his introduction, or Cassandra Cain *just* before she left her pops? So at the point she was field-ready, had move-reading and all that, but not yet traumatized by killing someone. The one we see spar with Bronze Tiger, take out a squad of commandos, and engage in bullet-dodge training.
Both fight to the death because hey, at this point that's what both of them do.