This is a stand out aggression card, a highlight in any deck capable of including it. There aren't many good aggression attack events, but this one is an exception as long as you are running a “fist” deck that can reliably trigger it. It can even be better than your hero-specific attack events. The only limitation is that you can only stun the villain once per turn, so the more players you have the greater the chance you both want to stun the opponent and end up interfering with each other.
Hero Action (attack): Deal 4 damage to an enemy. If you paid for this card using only resources, stun that enemy and draw 1 card.
"Smashing is what Hulk does best!" — Hulk
So how would this card work on someone with stalkwart I wonder. You don't draw 1 card because you don't stun the enemy? but you do give him a stun count...does that count?er... — Kageshira · 1
You still draw the card. There's no arrow between "stun that enemy" and "draw one card" that would make the stunning a requirement. The same is true if you defeated the enemy. — MightySchoop · 7