Astelnair is a mod that adds new creatures and much more.

Nope, Uriel Septim. Here, you can only change the standard ones. Even models and textures are only standard. The game is locked down on this and ignores everything new. I modify the clone creatures and use some technical tricks, but that's all you can do. The model system here is also unique.

Added 2 hours 13 minutes ago
And you, Uriel Septim, are to the right of me. As it turns out, you can add more, at least as many retextured units as you want.