What attitude does an average tsundere have in D&D terms?

[SangoProduction]

Hostile = Will take risks to hurt you - possible actions: attack, berate, etc.
Helpful = Will take risks to help you - possible actions: Protect, heal, etc.

Of course, then there's the fanatical tsundere, and the ones who rip of their love interests' head and drain their insides like a spider so they can become a vampire thing, and then do it again the next night....but I wouldn't consider those exactly the average.

[ThatOneShrroth]

Well, if we're going with the average tsundere...or slightly off-average, your choice...You could add something along the lines of them trying to prevent others from aiding their love interest. If there's something I've learned from watching a certain pink-haired yandere, it's that they really don't like it when someone else touches their love interest.

[Greenish]

Helpful, but not because they like you or anything.

[atemu1234]

Helpful, but not because they like you or anything.

Definitely helpful. But not friendly.