Rare monster Mod pool restrictions

A3 - Normal. Just hit a Rare River Hag with Temporal Bubble and Trail of Ice.

Coupled up with the Drown mechanic or whatever it is, that's a splat for anything melee driven.

Maybe have restrictions to mods for certain base monster types?

(Nevermind that I'm coming slowly to the conclusion that perhaps the River Hag itself is massively overtuned. I've had up to 6 attacking me at once, which definitely took the fun out of that instance. Restart at checkpoint for me.)

Trail of Ice is especially oppressive, it's like nothing I've seen in an ARPG. You go from struggling but managing, to "I can't do anything" instantly.

Worse yet, even if you prepared for this situation by equipping GGG's "solution" of a Silver Charm, they only last 6 seconds (3seconds 2charges). Hope you killed that rare in 6 seconds! hah hah