echoing above, kyurem's stats are massive and let it take advantage of freeze dry much better than any other user.
these 10 are the only FE mons with freeze dry in the game, beyond kyurem it's alolatales and then you have fringe stuff like lapras, articuno, cryogonal, and glaceon. the rest have either too little SpA or are just bad in general, and of the ones that look workable none of them bar glaceon even break 100. kyurem just stands leagues ahead of the competition with its huge bulk, attacking stats, and decent speed tier. i think this move will be fine, which is great because it looks fun to play with and might breathe some life into a couple mons, of note lapras which gets water absorb and has decent coverage + solid stats except speed.
thinking abt kyurem more it's definitely going to be a top threat as always but the customizability of defensive cores we're being presented with also helps alleviate the issue of finding a good answer, even if a foolproof one is difficult to come by. this is bolstered by tera preview allowing you to make informed decisions on what beats what.
:heatran: tera ground tran is already poised to succeed in the meta solely due to it's fantastic typing and great movepool, while also doing well vs a number of kyurem sets, taking neutral or better from everything outside of focus blast, body press, or tera blast. having a check this splashable will help a ton.
:azumarill: in terms of pure "counter" i don't think it gets better than tera ice azu, yeah sap sipper over huge power is really painful but azu has a very deep movepool, you can definitely make a good support set out of it. earth power is your best click here and it's really not that great (252 SpA Choice Specs Kyurem Earth Power vs. 252 HP / 252+ SpD Azumarill: 123-145 (30.4 - 35.8%) -- guaranteed 4HKO after Leftovers recovery). the big problem is gonna be passivity and lack of immediate recovery.
:dachsbun: similar strat to above, worse at taking hits than azu but it actually has recovery and benefits a lot from getting its ability activated.
:clodsire: huge special defense means even specs draco maxes out at <60% if timid, paired with tera ice and you're not awful into it unless it's some hokey physical set. you do have to fear specs earth power but at that point it's locked and much easier to pivot around.
:florges: yeah lets not forgot abt the flower veiler, icicle spear sets can be scary but all the special attacking ones are gonna struggle unless it's fairy freeze-dry or god forbid STEEL COVERAGE. if you're that worried about getting freeze-dried just have your tera type be different from fairy and be prepared to tera florges often, it's not like that's a bad strat given it can serve as a bulky wincon.
:frosmoth: the changes to rocks means leftovers might be more workable now??? at the very least it shouldn't be as deathly afraid of rocks and thus knock anymore, bulky qd sets could easily use kyurem as setup fodder moreso when you factor in your own tera.
there's also the different weathers which can be tailored to make your team even better at taking hits, though that starts to get into very vague territory and is fairly limited since they override one another, and can alter how your team deals damage as well.
