"Oh, just you wait. I have plenty of tricks up my sleeve." What's the fun in telling Dabi all of his secrets when he could surprise the other man and watch the expression on his face?

As the turns come around again he does fold, propping an elbow up on the table to cradle his head while he talks to Dabi.

"I did, eventually. It took a bit of doing -" and some summoning of alternate selves that he still doesn't quite fully understand, plus someone sacrificing themselves - "but I did eventually manage to get a blade of light formed to cut through him. It's the only way to permanently kill his kind."