Spiritual kin is based on the multiverse theory, and that you were what is currently depicted as fictional in a previous lifetime where those events actually occurred. All kins are valid, since there are infinite versions of every verse.
-Fictionkins-
-High-
Yamei (noncanon) - One Piece
Tomura Shigaraki - My Hero Academia
Princess Luna - My Little Pony
Satoru Gojo - Jujutsu Kaisen
Prince Gumball - Adventure Time
Uraume - Jujutsu Kaisen
Mitsuri Kanroji - Demon Slayer
Vash - Trigun Stampede
-Medium-
Chifuyu Matsuno - Tokyo Revengers
Joseph Joestar - JoJo's Bizarre Adventure
Judy Hopps - Zootopia
Boa Sandersonia - One Piece
Junpei Yoshino - Jujutsu Kaisen
Yoshi - Nintendo
Tetsutetsu Tetsutetsu - My Hero Academia
Pearl - Steven Universe
Jean Pierre Polnareff - JoJo's Bizarre Adventure
Frisk - Undertale
Jewelry Bonney - One Piece
-Low-
Fran Bow Dagenhart - Fran Bow
Denki Kaminari - My Hero Academia
Shiromori - Mystery Skulls
Kara - Detroit: Become Human
Cat - Stray
Huntress Wizard - Adventure Time
Markus - Detroit: Become Human
Takeshi Kovacs - Altered Carbon
Allister - Pokemon Shield
Bea Santello - Night In The Woods
Romelle - Voltron: Legendary Defender
Amaya (noncanon) - Demon Slayer
-Otherkins-
Rocky Mountain Elk
Wooly Mammoth
Siren
Demon (succubus)