Indeed. The Sorceror’s Skull is what you get from the run of the mill sorcerors in the Exiled Lands. The Magi Skull is from the encounter bosses, the lieutenants of Kurak. You turn them in at the new camps added in the Testlive version of the game. Which is why this post is under Testlive.
@rolee9309 Sorcerer’s skulls drop from the Sorcerers you find around the Exiles or Siptah maps. They are not “mods”. It’s part of the new update that Funcom put out recently. Maybe you should try playing on Test Live before commenting on things you clearly know NOTHING about.
When you turn the skulls in (with or without the sorceror still attached to it) you will get a handful of coins called Ancient Obolus, some Steelfire, Alchemical Base and Demon Blood.
You can then use the Ancient Obolus to buy either converted thralls (T3, and only hyborians for some reason) or supply packs (same as the ones the bearers drop). You should also have the option to buy the Armor of the Mad Prophet, but it’s not available on the testlive right now.