[Verjigorm]

Yes, my Lich (or any other) Immortal unit will never retreat as long as there is a white candle on the province because it cannot die. The only way to rout an immortal is to (a) be defending and (b) reach the 50 turn limit.

The "army routs" message may display multiple times for any of a number of reasons during the battle, but no immortal units will retreat. Immortal, non-commanders such as Vampires and Fey Boars will retreat if they have no commander, I believe.

I have never seen an immortal unit retreat before it dies including to this "total hp" retreat indicated above.

One thing about Immortals is that they do collect a significant number of afflictions. Your best bet for dealing with them is to try to keep a nasty affliction on it such as "Blind" or "Feeblemind" both of which can be induced by magic weapons. The phoenix, who can die multiple times in each battle in CBM with it's automatic Phoenix Pyre I have seen collect as many as 7 afflictions in a single battle all of which, of course, were healed by my lovely Arcoscephalean priestesses ^_^. Immortals also have automatic Rejuvenation effect even if it doesn't show up--they will randomly heal afflictions each turn.

This won't work well, of course, if you're up against healers such as Arcoscephale or EA Ermor or if your opponent has Gift of Health or the Chalice.

Also note, that my lich is a Master Lich which is the weakest immortal chassis--it's a rainbow. The regular Lich is significantly more powerful and can be used as a thug or SC, but generally lacks the wide variety of paths the Master Lich has. SCing a Lich requires at least one wish for "Power", but requires only minimal equipment depending on your choice of paths. Minimal gear is always best for Immortals because you don't want to be afraid of kamikaze. I usually like Death/Astral minimum often with a touch of Air and or Earth for the big Lich.

(I'm an Immortal pretender freak btw).