Can the spell " Create Undead " turn someone into a permanent follower or was that a glitch ?

Hello everyone, hope you're having a good day

Fairly new to this game ( level 11, i've just met with Magnus and i am currently messing around Tarant ) , i have witnessed something i can't tell if it's either a feature or a bug :

At the end of a fight with some bandits in Tarant, i casted the spell " Create Undead " on one of them, simply for fun. After a while, i decided to break the spell as I was starting to get low on mana. Then a miracle of Necromancy happened : the thief stayed with the party, despite me not holding the spell.

This thief called " Half Orc Thief " now calls me master ( which makes me a really proud necromancer ^^ ), and will answer to my orders or carry my stuff like anyone else on the team.

Yet the way i have obtained him feels a little bit buggy when i think about it : i believe he got stuck in the Halls room basement instance. I might have left him there, broke the spell outside, came back to have the surprise to find him waiting for me. Plus it seems like switching instances ( going into caves and the like ) makes him glitch as half the time he disappears during the loading screen, only coming back when i fast travel. However, his little square icon is always there.

I now cast the spell Create Undead to every foe i kill in the hope to extend my undead army, but he's the only one i have managed to permanently rally to me. Wouldn't it just be a glitch then ? But why would there be lines of dialogue making him call me his master ?

Can you enlighten me people ? I am at loss !

 

It's definitely a glitch, probably brought on by the creature getting stuck on another level. There used to be some shenanigans you could pull off with Meta to create an army of undead but that was fixed in the UAP. I doubt that's the issue here though.

All created undead have the same dialogue ("yes, master") so that's nothing special. Necromize Virgil and he'll also call you master (no voice though), only conjured spirits have special dialogue depending on the character raised.