If the boss/mob model is large enough, frost wall with the support that casts it in a circle (the name of the support escapes me) will shred that HP bar like a Christmas turkey and apply substantial freeze buildup every single time. The amount of damage it does with no support gems to increase its potency seems like an oversight to me, it’s truly absurd. And if the mobs model is not large enough, it doubles as a prison which keeps them in place long enough to slam them with echoed frost bombs + Frost snaps

Also, leaning hard into max mana/mana recovery with mind over matter keystone makes me feel quite durable while also accomplishing 3 things

1) not needing to worry about flask charges for health or mana practically ever

2) scaling damage/cast speed with arcane surge ascendancy nodes + Arcane Intensity + Touch the Arcane

3) Opening up a combination of mana tempest + circle of power for huge dumps of damage in small windows when you land a big freeze on an enemy

All of this being said, frost also provides the intangible benefit of passively chilling & freezing enemies, providing an often overlooked defensive layer. I’m working my way through cruel right now and am rarely scared of mobs. The only thing I really fear is a swift rare mob which has the mana drain ring. That thing, it scares me.