@Salfaro
I might be wrong but here is what i understand :
The MC died and someone sold his corps to Hack who gave/sold it to the necromancer who revived his corp as a fleshman
The fleshmen(lower undead) don't keep their memories but MC for some reason has his old memory/is self-aware
Ghouls can survive after the necromancer's death but not the fleshmen
The undeads under necro can never flee since the necro know where his undeads are at all time(more or less) if the MC want to be free the necro has to die, he was waiting the right time
The necromancer though the salve was laying since End(MC) is supposed to be a fleshman (also that's why the MC tried so hard to hide the fact he was a ghoul)