Jack flirts with a lot of people, in a friendly way. He's quite drawn to Elsa because of their powers, but since she's never expressed interest in that he's chill.

Jax doesn't have it in him to regret that kind of thing.

And a little of both, actually. I want to play him as if he went back to Berk and forgot his time on the island, bring him back from the end of HTTYD2, and have him slowly recover his memories.