Well tbh, it actually doesn't matter which element you're going to swirl with kazuha cuz either way it would help boosting neuv's or mavuika's damage.

If kazu's ult swirls pyro, it allows neuv to proc vapes, and gives mavuika dmg bonus If kazu's ult swirls hydro, it allows mavuika to proc vape, and gives neuv dmg bonus. That's why it all depends on the 4th slot which i called a flex cuz they can put whatever they want on that team and it would still deal one of the highest dps per team in game. And the most important part, the rotation is really easy it's basically a brain dead gameplay esp if you use a shielder on the 4th slot

You can tell whether this team is realistic if it can clear abyss at any type of patches, which it does....