So Fun fact i've just fallen into a deeper rabbit hole than i should have when teambuilding for this wacky OM, i literally just created this account to talk about it and it has to do with these two sets

Froslass (F) @ Rollout
Ability: Snow Cloak
Tera Type: Ice
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Triple Axel
- Poltergeist
- Destiny Bond
- Will-O-Wisp
the description for rollout is that it "doubles in power with every hit and repeats for five turns" wich means that, the second turn that you use poltergeist you would be nuking everyone with a 220 BP STAB move (AND double every turn after) but it also means the multi hit moves double in power after EACH HIT with something like icicle spear or rock blast it would go 25/50/100/200/400 if it hits 5 times or 25/50/100 (3 hits on turn 1) then 200/400/move fails (3 or more hits on turn 2) BUT with triple axel specifically that's when shit hits the fan because triple axel also raises in power after each hit, According to what ive read on other forums and the description for triple axel it should THEORETICALLY go like this:
1st hit is 20 BP as normal then 2nd hit raises its BP to 40 due to triple axel and doubles to 80 due to roll out then 3rd hit goes to 60 due to triple axel and then rollout QUADRUPLES it to 240 giving a total of
340 BP + STAB on TURN ONE, but there's more. you're forced to click triple axel again on turn two and the roll out multiplier its STILL active, so on turn two the first hit its 20x8 for 160BP second hit is 40x16 for
640BP!! and since you used all 5 multipliers the 3rd hit doesn't even come out and the move fails, or at least that is how i THINK it should happen, i havent tested it yet.
the second set is:

Cinccino @ Echoed Voice
Ability: Skill Link
Tera Type: Normal
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Tail Slap
- Triple Axel
- Tidy Up
- Thunder Wave
Echoed voice also scales but it does so by 40 BP every turn not every hit, wich means it simpler to predict, tail slap + skill link would be 125 BP like normal on turn one then 325 BP turn two adding 200 BP every consecutive turn its used up to 225x5 or 1125 BP after 5 turn, but then again triple axel ruins everything because i have no flippin idea how it interacts with BP increases! is turn 2 triple axel 60/80/100? is it 60/40/60?
is the power increase of triple axel a multiplier that applies on TOP of the 40 bp increase of echoed voice? bc then it would be
60/120/180.
TLDR: triple axel interacts weirdly with power increasing effects and im gonna go test it to either destroy people or get destroyed myself wish me luck
UPDATE people!: it doesnt work :(
but that doesnt mean the interaction is not interesting, first thing i got wrong, itemized rollout doesnt lock you into the move you clicked, but rather locks you into roll out itself, even if you dont have it, you get forced to use rollout until you used all the multipliers or miss, second thing i got wrong. with triple axel it seems that the bp increase of triple axel and roll out dont stack second hit does damage as normal while third hit comes at 80 bp instead of 60, the interaction with 2-5 hit moves does work closer to what i predicted, first turn doubles its damage after each hit but in the second turn you get locked into rollout with its multiplier depending of how many times you hit with the previous move (so if you hit 3 times turn one, your roll out will come at x8 turn 2 and continue as normal) so while not insane its a decent niche
echoed voice however doesnt do anything, it seems or at least i think that the move its programed to apply the bp increase if you used echoed voice itself the previous turn instead of apliying if you use the same move you used last turn, so theoreticaly if you were to somehow use echoed voice while having it equiped (wich its not legal) then the bp increase would apply to next move you use. but it makes sense since fury cutter a different move that does something similar does work as youd expect and hence got banned for being to strong. i would have liked that the rollout interaction worked as i predicted for some sort of hyper powerful band/specs, but it would have been too powerful