My knee-jerk response to '...what the animation was drawn from...' was 'wait, there's an animation?'
Robin literally just runs at you until the sword she/he is holding happens to be in your gut-- it'd always looked more 'running with scissors is dangerous' than actual stabbing. While it's a misery to have it as grab bait with that quick stop and all, it makes for a simply incredible mixup tool given its low visibility. Barring shadow sneak, it seems one of the very few attacks in the game that can take advantage of a limited profile.
It's a pretty dreadful mistake to spam it, given how vulnerable Robin is to shield-grabs without a dash attack that conveniently stops right in front of foes with plenty of lag to be grabbed, but occasional use is really quite rewarding. Also, it can sometimes combo with Arcthunder/Arcfire if foes are hit close and low to the ground, if, say, a Fair/Nair/tilt/grab/Nosferatu follow-up isn't ideal.
Actually, there's probably less moves that don't combo into Arcfire... Ah, but I'm getting off topic. This thread has me wondering how many times I'll think 'I'mma shank ya' or such such silliness every time I send someone offstage (though rarely an outright KO, of course) with this move, now. XD