Pain-suppressing spell Allister recommends pairing with immortality, since immortality does nothing about agony.
In his 13th Edition note in the Dungeon Anarchist's Cookbook, Crawler Allister stresses that Immortality does not protect against pain, and advises that if you can, you should couple immortality with the Numb spell — because pain with no respite takes its own toll.
Carl went into Khepri's feast hall without it. Reassembling from the Waffle Maker blast, he felt his pulverized bones knit and thousands of miles of nerves light up like a power grid all at once, and reported that it hurt more than anything ever should; a process of seconds that felt like a year.
The missing companion buff whose absence makes Carl's survival an ordeal.