This is a very small thing, but I wish the action was an attack so it would trigger Bucky's ability for killing minions. Instead, you get an unfortunate anti-synergy where using this to kill minions misses Bucky's ability completely.
That's not to say you shouldn't use it as Bucky though. After all, it can bring down a minion with 5-8 HP so a basic attack from Bucky can finish it off. But it's not quite as consistent as it could be.
Besides that, this is a pretty good card. The initial play to get Captain America's Shield is going to be 3 ER in total. That's between playing this, paying a physical resources, and paying another resources to play the Shield.
For that 3 ER, what you get is:
- +1 DEF
- 1 Retaliate
- The ability to pay 2-ER to deal 4 damage once per turn for the rest of the game.
The last thing does requite a physical resource, but you're playing Leadership which means you better be playing Clarity of Purpose. This should be no problem to fulfill consistently.
3-ER would justify the first two abilities alone, being only 1-ER more than Ronin while letting you have allies. It would also justify the third ability alone because 4 damage every turn trivializes minions for the rest of the game. The fact that you get all these abilities is just a nice bonus.
The weird thing about it is that it's not a very leadership card, and therefore doesn't play well with most Leadership things. If you think about it, this is a Protection card tacked on to an Aggression card, only in Leadership for thematic reasons.