Any Raspi player will primarily take models with Frozen Heart.
Expect her overall crew to be slow as her general tactic is to use Frozen Heart minions as Line of Sight proxies for her spells. The Ice Golem is tough to kill, but from what I've seen its too slow for any objective work, however at this size of a scrap it will be annoying to even try and kill. Ice Gamin are annoying, they're not that good, but you can get bogged down trying to kill them in melee and then when they die they shatter and hurt your models. Blessed Of December should be included as she is damn good for 'tina, being very mobile in a crew of literal glaciers. Snowstorm is a big hitter and if he's got one and assuming he know's you're going gremlins, it might be a good, but painfully expensive choice as its pretty hard to kill with ranged attacks.
If he takes mercs expect Von Schill for... well its Von Schill, he explains himself really.
Expect the Essence of Power totem as the Wendigo isn't as good as it should be.
Mostly I can tell you that at 25ss you won't see Kaeris, as running Ice and Fire means having a very split crew to run. The overall crew will be slow but tough and a lot of the ranged offence comes from Raspi casting through her crew while sitting in some bunker out of LoS. That said if he takes Blessed of December expect her to do the legwork, if he takes Snowstorm... well just remember Malifaux is a game being played for fun, offer to swap crews and replay the scenario...