Something I really want but doubt will happen is making undead equal or slightly worse to when they were alive and level and train them like normal companions, this would be broken and insanely dump because it could reach a point where undead could hold companion slots and then just replace the ones you already have or just kill them and raise them as undead companions, but I would still love something similar to be added because a permanent undead companion is perfect for a solo necromancer play style and also I love the I idea of having a compendium of undead I've raised and stored to be be used as a summon the idea is amazing but may make necromancy too powerful but I hope we can at least save undead like the "second marriage" wand.
