Just did it second time with lvl 14 skeleton reaver, quest was complete pushover, absolutely nothing dangerous. Final boss seems tried to teleport me (I got "continuum destabilization"), but luckily I had amulet of teleportation with 50% resistance. For comparison, first successful quest with ~lvl 20 arcane blade was a hard thing - one-death by the group of light horrors. And my first failed entrance was a complete nightmare with near invincible 500% resist all tentacled thingy.