thank you for the reaction !! this vocal texture is normal for her- she has a few songs where she sings almost entirely in a higher register & has a "cleaner" "sharper" texture, but otherwise she intentionally adds vocal fry and vibrato especially in live performances. i think it works with her style & dynamics !
If you haven't, I believe you MUST react to her First Take of her song Fire. It is also opening to the anime Dororo. I think it fits her super well and personally prefer it to the original 😆
Great reaction. :) I have one recomendation, not from anime, but Queen Bee, they were one more time in The First Take after performance you reacted to, first time as band, not only Avu-chan (vocalist) and Hibari-kun (guitarist), and they performed one of their older song "Teppeki" or "Impregnable" in english, from 2012. In "Mephisto" you can see just idol character played by Avu-chan, but "Teppeki" is sad and emotional song, very personal for Avu-chan and there you can see 100% of real her, amazing performance and song, for me personally much better than "Mephisto", because "Mephisto" is just song made to anime, but "Teppeki" is about true Avu-chan feeling and experiences. Oh, and there is english translation of lyrics.