Quote Originally Posted by danielxcutter View Post
Having a caster level is not the same as being able to cast spells to be fair. If you’ve blown all your slots you have a caster level but can’t cast.
Yeah, this. Xykon didn't cease to be a sorcerer with caster level 25, or whatever - he simply stopped being able to cast any spells.

The SRD is about as explicit as can be when it says "Each lich must make its own phylactery, which requires the Craft Wondrous Item feat." Either the rules are being ignored - which this thread assumes is not the case whenever possible - or Xykon is making use of his Craft Wondrous Item feat to craft his own phylactery, with Redcloak helping him, presumably both giving him instructions and providing spellcasting services when necessary.

There's definitely some RAI fuzziness here, since nowhere in the rules does it say that a lich can receive help from an outside source, but none of that requires us to assume that the rules aren't actually in effect.