It's a mindless automaton, knowing what to do is also a reward for reading things (+1) and it's two-steps, you need to heat him up with lava before luring him to the anvil.
The solution a lot of games would take to a puzzle heavy encounter would be to add "phases" to the combat, such as 'figure out the puzzle', then be forced to burn him fast while he berserks, but I don't particularly like that, so I'm happy with what there is.
As for being low level and beating him, with your logic it only makes sense with some kind of non-class/level element, like prying the power gem out of his chest, it's a work around to the brute force method you can't manage.
