Yeah, its a bit too spoilerish equipment-wise and some location-spoilers too .. so I'll just give you the necessary mods to obtain:
Permanent immunity to magic( unless the enemy casts Pierce Magic/Shield and/or Lower Resistance), and permanent 95% base physical resistances( immunity and healing for 2 turns with Hardiness).
Mods needed,
1) The Ritual (requires ToB)
2) Gebhard Blucher's Lich in the Docks
3) Ascension
If you ever want to know if you have it all, and are willing to be spoiled ...
check
*spoiler* this *spoiler* Topic [img]smile.gif[/img]