Jormungand

Jormungand is a orginal character introduced in Seven Deadly Sins Grand Cross game

Fenrir
She sees him as a older brother due to Loki adopting him first and tends to call him “Older Brother Fenrir” a lot and gets along with him well

Trivia

 * She based after the serpent of the same name from Norse Mythology
 * It’s unknown what her race is due to Grand Cross labeling her a “Unknown” race and the Rangarok story (So far) haven’t told us what her race is