There is something to be said for testless damage. Sometimes, being able to just reach out and finish off a foe can be really, really good.

This card is in an odd spot because you basically have to have a foe that is "softened up" beforehand in order to get the most out of the testless, conditional one damage.

Beat Cop and Ambush can do that, so they are worth mentioning.

Also, Zoey's Cross can soften up your opponent for the final blow.

That means you probably want Taunt or Let Me Handle This! so that you can reliably trigger this card.

Ultimaltely this is a support card that might be just a bit before its time. It isn't a lynchpin card for an archetype, as all it really does is let you either finish off a wounded foe or sprinkle some damage on them. I anticipate a weapon or effect in the future that keys off of "damaged enemies". Until then, this card probably won't get a ton of play (outside of some Expert builds that value the testless damage).

This is not the best card. But. There is a place for it.

Mano a Mano is primarily let down by its restriction of "First action only", this means that it cant be used by a dedicated fighter to tackle down enemies engaged with their dedicated cluehounds.

This card is good in decks that go out of their way to very literally "hunt" for enemies on their own. You use "Let me handle this!" and On the Hunt to ensure that enemies that might've spawned on your friends get spawned on you instead. The circumstance where Mano a Mano is good is when enemies spawn on you and you can start off a fight right in their faces and these combat support cards can make that happen manually.

The most efficient way to put this card to use is in decks for characters who benefit from the monsters they battle, William Yorick and Roland Banks come to mind. Zoey Samaras can also put this card to good use.

Other cards that synergize include: Guard Dog and Beat Cop for more auto-damage. Evidence! to then turn hunted enemies into clues. "I've had worse…" to fuel the warmachine through sustained battle. Every single weapon, obviously!