Hey, @geneeverett.

The line does work, and Iron Man certain has the toys. Stark's a billionaire, too. He's certainly not afraid of escalation, either, and he does have a hard time knowing when to stop—all things Joker would gravitate to.

The question is, does Stark totter on the edge, walk the line like Batman does, between brutality and killing. Joker is fixated on walking him over that edge, even and maybe especially if it's at the expense of his own life. Or at least some versions would. :)