Not sure exactly what that does but currently necromancy school wizards are pretty solid in my opinion. The play test left out the undead minion spells for understandable reasons but I’m sure they’ll be there for the core release but regardless necromancy has gotten a big boost in attack spells and are a solid alternative to evocationists for battle mage.
Just looked them up and you could possibly do that as an evil cleric, (Urgathoa, Godess of undeath and gluttony) I’d stick with the wizard. Sorcerer could work later on but there isn’t a good bloodline for it right now. PF1 had an undead bloodline so I suspect the final product will too. As stated the play test doesn’t allow for the undead horde right now so necromancy is pretty limited to attack spells.
So you've posted in the playtest section for the Pathfinder 2nd edition. I'm not sure if that was accidental and you meant to ask about Pathfinder 1st edition.
In the Pathfinder 2nd edition playtest, there's really not much support for necromancy right now. There are spellcasters who get necromancy spells, but nothing that can create undead minions. Wizard and Sorcerer with the arcane spell list probably works best, but that's about the limit of it. The necromancer wizard's powers are kinda useless, so there's no particular reason to be a necromancer specialist other than for flavor reasons. Urgathoa (the goddess of undeath) actually gives some pretty nifty undead-related powers to clerics, but at present time there's no way to actually use them so she's completely useless. However, her powers are very strong on paper so she looks promising for the full release if the rest of the support is there.
In Pathfinder 1st edition, for the most part there's no need to do anything special. Just pick a class that gets access to necromancy spells, learn those necromancy spells, and you're good to go. Necromancer Wizards work beautifully well out of the box, the Gravewalker Witch archetype is another supremely flavorful options, and personally I quite like Sorcerers who just pick up a bunch of necromancy spells (spontaneity is really nice, and the use magic device skill lets you lug around scrolls and wands for the occasional divine trick you just can't do with arcane magic). On the divine side a cleric who worships a deity of undeath will do just fine, as will an oracle.
