Demon lord and Heroes sketch concept

I love the partial transformations look; she looks like she thinking..."Yes...i did it, I came back from the cusp of death. My daughter's will not denied their mother and my monster girls will not be helpless and alone, I can continue to be their for them". Just...a look of satisfaction in the form of a funny smirk. Also the hero reminds me of Bolo from Shantae.

Could the partial transformation be the normal form of the hero turned demon lord. While the one of the left be her battle form. That way she can still pass as being human if she tired without the need for magic. Thus able to trick her former allies easier and 'convince' them to join her new cause

This will be awesome!

I second Gustavo and offer a similiar suggestion, of perhaps one of the members falling for or being charmed by the transformed hero. Rather then just being forcibly changed and all. Also if it's a hero after the Demon Lord, then the hero HAS to be a religious zealot. One that eats up every word that damnable kill squad, called a church tells them about how monster girls are bad and deserve death. Plus I don't feel like we get nearly enough changes based on retribution, or characters getting what's coming to them or otherwise. So it'd be a nice change of pace.

Very good!

It would be nice to have a party member watch him getting turned, maybe even being the reason he falls to full demon status

The partial transformation is so good,can imagine how the demon lord take over the body.

my suggesgion is to not have the hero become a exact copy of the demon lord, some minor differences in appearance. though yes allies would be very welcome, elf bow woman or female caster are good ideas.

Really like the partial transformation, feels like fusion, awsome xD

Oh wow, I can already imagine the hero become another of the Demon Lord's many allies.