Idea for syndicate dagger

[Frank_Stein]

Weaken it's overall damage, but give it a new ability to instant crit a person if attacked from the tile next to them that's behind the direction they're facing

A backstab kill, only deliverable on an unstunned standing target

[Lady Birb]

I like the idea, but think the syndie dagger should stay as-is. Maybe add a butterfly knife traitor item with this effect, because tf2.