RTF is a global modification that replaces all towns in the game.

And to which faction will this unit belong? It partially resembles undead, but only partially. And I don't think it will be a demilich, as I understand it.

This is not a demilich, but a resurrected mage enslaved by a necromancer; I saw it in D&D, I think some necromancer makes them in the Underdark, but in form, it's a demilich.

Combining with elements is another idea that I'm too lazy to develop – a necromantic slime and a lich combined with a stone golem; it's tedious to create upgrades for such units, so I decided to put all the ideas together.

But now the units are questionable because undead in general are being reworked.