How do I run this fight? (RPG Spoilers Ahead)

I'm not going to say that my players are awful at diplomacy, but when presented with the option of either making peace with someone who is punching them or continuing to punch back until that person is defeated, they tend to pick the second option.

That said, in Prime Wardens #86, if Haka gets impatient and starts beating the stuffing out of them and their new friend Tempest, in all likelihood, they aren't going to continue to try and talk her down. This is... problematic, because the pdf doesn't tell me how to run Haka if she's a threat. What dice do I roll? How many hits can she take? Do I just make her a D12 Lieutenant?

Basically, what should I do if my players want to straight up fight Haka?

If they don't wanna talk it is fine. they can lose out on that, but the game will not continue long enough for that to come into effect.

I think the official is rolling the environment and make her actions of that. I Would just roll whatever dice I want and make her do whatever. They do not have the power to stop her physically, and she cannot be killed. If they only speak in fist fights make sure she hits them hard enough to make then think about talking.  One can also say she ignores all their attack for they are too weak. It might be though but this might be a good teaching moment.

My gut response is along the lines of "slap them till they puke", but the message might get lost in translation.

I'm with speedyolrac, this is a good opportunity to teach them not everything can be solved through fighting. Make it clear she just can't be taken down through fighting and if they complain you're cheating, point them at the wiki's page for Haka's Letters Page episode.

I'd have a hard time justifying "the heroes cannot win this fight."  She's tough, but standing up the the whole Freedom Five+Unity at once?  I don't think so.  Especially since we'll have full stats for her when the full game comes out.

I'm thinking what I'd do is make her a "phantom" full villain with "real" HP.  Except that she just soaks the damage, takes out Tempest at the earliest opportunity, and then the next scene begins with her still hostile.  If the heroes attempt to defend her at any sort of risk to themselves, that counts as her "convince her to listen" the first time and then "convince her the heroes aren't villains" the second time.  If, after the battle, the heroes still persist in attacking her, she tries to flee.  If the heroes pursue her... well, only Legacy and Tachyon have a chance of doing so, and that fight she can win, especially when they're weakened by the spirit battle.

I more made my own suggestion because it seemed like this is a weakness in general with Raccoonoo's group, so it seems opportune to take the chance to open the group up to new ideas using an adventure expressly designed to be solved optimally using non-combat methods.

That's fair, and is probably a good plan given the rest of the adventures (that I've read so far).  A group that defaults to punching threats until they stop moving will not do well with this product.  On the other hand, I'm also worried that they won't enjoy these scenarios at all, so I'm curious to see how it all turns out.

For those Punch first, ask question later. I would let the hero develop some bonding time with Tempest, let the Heros and tempest fight off a few dinos before letting Haka in the scene. I would let Haka be very Vocal and very emotional. To her Tempest is Dawn, let the Heroes know that and how horrible Dawn is. Your group may fail at this and it is ok. Failure is part of comics.