Just thought I share this. Played the game second round using the same strategy and manage to get the Ring of Gaxx without scrath on my characters.

Two things. First the lich can't imprison Wizard Eye. Second the lich can only be hurt with +4 or better weapon. So I just use Nalia to call out wizard eye just before the initial lich transform to demi lich, move the eye in front of the skull head as distraction, than hast the characters with +4 or 5 melee weapon and what do you know...you're the proud owner of the most powerfull ring in the game.