I'm running a group of players through the Lost Tomb of Kruk-Ma-Kali in a Kingdoms of Kalamar campaign. It's 3.5 so I'm converting as I go. One of the unique creatures in the module is a type of death knight. It's not a template, just a nasty undead creature. It's got 16 hit dice and spell resistance. It's pretty decent at melee, but it's spell-like abilties are what have me worried. It's got a 20d6 abyssal blast, wall of ice, and all three power words as once a day spell-like abilities as an 18th level caster. Is this too powerful for a CR 12 creature? If so, what should I do to tone it down?