What are some potential undead-themed rewards/abilities for reading the Necromancy of Thay for a barbarian?
I'm running Descent into Avernus for my group and they're soon going to reencounter Raphael (from Baldur's Gate 3), who, for a price, will offer knowledge from his copy of the Necromancy of Thay (also from BG3). This is my way of introducing the Path of the Lich from the new Villainous Options in Unearthed Arcana to the party, who are about to reach level 11. (The twist I have: an item of great personal significance will be a part of the price to pay for this knowledge, which will also become their phylactery in his possession)
I will allow them to take the lich initiate feat and one other feat, providing them a total +2 to their spellcasting stat and the chance to take the final lich transformation for their feat when they reach level 12. I believe my player who would be most excited for knowledge from a book of undeath would be my barbarian. However, neither Path of the Lich nor Path of the Death Knight are of any use to a non-caster.
Do y'all have any good ideas as to a what cool undead/necromancy-related abilities would mesh well with barbarian abilities?
A thought that I already have is to give him a modified version of Danse Macabre (from BG3), where he has four charges to summon one ghoul at a time that explodes for 6d6 necrotic damage on death.