Bronz_Deck
An easy option for a companion, will be among those to whom you can give baka red. Too strong is too boring so: Kuriyama, Mirai: Beyond, Karin Uzumaki: Naruto, Sakura Kyouko: Madoka Magica. Each of them has a moment in their lives when they will not mind leaving for another world. Of the interesting things that I have not seen anywhere else: Echidna: re:zero, Phosphophyllite: land of the lustrous, Mavis vermilion: Fairy tale
How about nasu no yoichi as a companion? He has exceptional archery skills, he can be a great companion and friend, and you can even find a way to make him learn how to use elemental mana on his arrows, besides being something different, since I've never seen anyone use that character. Nasu no yoichi (Anime: Drifters