OOC: Grr. I lost my first try at this.
"I'm certainly have no qualms regarding an attack on an evil lich. Undead usually require prompt annihilation, lest they find ways to use their immortality nature to their benefit."
Darian pendanticly explains the abilities and defenses of liches, then concludes: "Of course, I wasn't even aware that psions could become liches, so Tulmercy may possess slightly different attributes. Still, very little should prevent you from hacking it to pieces or filling it with arrows. I'll need to alter my spells slightly, since Polymorphs will be ineffective.
The lich isn't so far away that Teleportation is required. When you take into account the time and effort needed to use the spell, riding out to face him would not be significantly slower."