[Shujin]

Yeah no, Canceling out Winterbite is a no-no.
I kinda want this to be passive because of the way you telegraph it to your enemy when you actively use it. You are litterally saying "Hey, either destroy my Ice resist, or don´t use ice on me atall!"
With the passive effect it atleast has the "First Surprise" effect sometimes.
Ice resist is already VERY situational.


Comparing "Similar" skills:

If I compare it with the other buff skills in the game that are "Similiar" to it, it would be Dark Shield (Which is also a almost never actively used because of the valuable Void energy it consumes, but thats a subject for another topic)

Which grants:
+15%Passive Darkness Res (which is a very common Element)
+up to 13 Res (Which also means up to 13 Dark atk, by the way, unless softcapped, and having some extra Res is always nice)
+last up to 8 rounds

Downside:
-Consumes all your Void energy, which is probably the reason it´s only used as a passive if anything.

conclusion: While it´s effect are good on it´s own, people don´t use it because the drawback is crippleing for VA´s, they need the Void energy elsewhere and would only rarely use this skill. But luckily, having it in your skill pool is already granting you a benefit against a very common element.

And well the other thematically compareable skill is Kraken.

Which grants:
+ 11 ice atk flat
+ 4 Ski (which is also a small ice atk bonus)
+ 4 Def
+ Ice elemental impact
+ Benefits from Enchantments talent "Prolong" (Up to 8 turns)
(+ You deal Ice damage, since when you use Kraken you most like have Elemental Augment aswell, which is a strong boost. But also not directly died to Kraken thats why in barckets

Downside:
- Elemental locked for Duration
- Wind Weakness 25%

conclusion: Very strong benefits Vs pretty tame drawbacks, the weakness is nowadays not even triggering the "Weak!" red text so you don´t need to fear giving your enemy extra momentum. (Cause of your general 1% San resist, you don´t need to equip anyhing special.)
And well, Insulate?

Which grants:
+ 30% Ice resistance (which will usually be hard countered when you telegraph it, so you can´t be happy about the boost for to long)
+ Ice walk... Which is neat I guess? Still useless on most classes, especially on your own thanks to many alternative skills for movement and Shukichi which never even allows you to walk normally, which is biting with Ice greavers secondary effect aswell. (Considering the aspect of it actually being able to cast on Teammates which is kinda cool! But that counts for the other two skills aswell. So no bonus here.)

Downsides:
- No real ones actually, besides it´s effects being underwhlming in general.
- Well you kinda have to refresh it often, since 3 turns duration isn´t really long atall. And if you have to use it on teammates aswell, good luck keeping it up.

conclusion: Thematically okay, and looks like a decent effect on paper but in praxis you won´t really benefit from it at all, thanks to the many ways to counter it and it´s short duration. IF we only make it benefit from Permafrost in duration, it won´t change the fact that the skill is very situational and in all other situations it´s simply eating a skill slot away without any use. And for the few times it´s being used it´s only helping a bit with "refreshing", which is ok, yes...But still kinda meh?

Pretty much why I still believe that simply prolonging a "useless" effect won´t make it suddenly be used. It certainly needs a little more before it isn´t just a skill slot eater that gets maybe used once in a (Ingame) Century.
I can´t really think of anything else, this skill could grant to make it also attractive to be used in Teamfights (for non Ice users).
And for Ice users the Ice Atk is probably what they want, unless we add another line of "If under Insulate your certain Verglas skill under Fox tree get additional effects!" for team verglas user, Not sure if thats what we want though. Fox tree is kinda lacking for the FP costs, with exception of Expand Ice which is because of it´s range reasonable. But there are already plently of topics about that.


long post short:
Insulate needs some love, over longer duration, before it ever finds it´s way in the skill pool effectively! Support your local Verglas rights activists and adopt an Insulate for your own skill pool! It needs the love before it dies out! Don´t..... Let it go!~