We often talk about homebrew resulting in creatures being OP in Bg3, however I am concerned that the Adamantine Golem in the Grymforge is significantly underpowered.
For the record here are the stats on this thing.
It's a CR 25 creature that never breaks down or degrades in any way. Its trample attack is 14D10, it is practically immune to magic. It gets two attacks per round at +18 to hit that do 10D10 +10 damage per attack.
I get the need to make it vulnerable using the Lava, that is fine. However, the Lava would not degrade its ability to one shot two players per turn if they get near the thing.
Despite all this it's still totally killable at full power under the conditions of this encounter if players can move quickly as its max speed is 20 feet per turn and the Forge Hammer hits for double damage if you get him under it.
Hopefully we will see it at full strength under a higher difficulty setting.