I like the dagger set idea. But, as mentioned, we already have a bunch of dual knifey sets already. So maybe instead of daggers, you poke your opponent in the chest with your fingers.
Criticals or Fury can cause a staggering back effect - not like knockback, but it forces the opponent to step back. The pokes do psionic damage and the opponent is incapable of attacking back. However, each chest poking attack builds up levels of Anger in the opponent. After four levels, the opponent can do it's biggest attack at 200% damage and with a +50% to hit buff.