A decent damage trickle for any ally you're planning to use 3+ times; handy in that it works on Thwarty allies, not just attacking allies. Plinks off Tough status, softens up or finishes off minions so you don't waste full attacks on them, etc. Note that this effect isn't itself an attack, so you can use this to help work around enemies with Retaliate, which can sometimes be a problem for allies that attack.

A staple card of "Voltron" style decks that run Avenger allies.