MidGard
MidGard:Permanent only if one etched an ability that utilizes that mutation. For example, Sphinx's eyes were kept because Felix etched *The Truth Eyes*, if he didn't, he would have lost both mutations.
Seeing his tail disappear like this, my hope for wings slowly crumble away. it seem midgard plan his true appearence to ramain human afterall. (Tiny mutation such as eyes or hair colour did not count) So, temporary tail or temporary wings, temporyry holes on skin (or not? They are tiny after all) and the horror, temporary sucking cubs or tentacle).