[Whistle.] That is quick. [Law saw Kakashi move back when he was sent with Sakura.]

But yes... I can see where the immortality is a thorny issue, even given the wings here. [Hmmm... now how would he deal with that long term if he had to? Oh yes, that's how.] Would be tricky, especially with no forewarning...

[Welp, now he does have that. And a couple plans of attack in case the bastard does pick a fight.]