There’s a way to make it, even with less textures, we start with only 1 finger with 4-5 frames. (used custom and pixel art style for simplicity)
Then we can clone it and then rotate it to make it like the normal wings as that’s how also wings are made:
I know, this post is old but I just got this way from my mind, even if this animation didn’t get added to Thundercluck, it will be nice to at least see it in another boss.