Ok that is from a fanfic I wanted to make, now is in pause because moonshadow was taking me some time as well my studies but, now backstory.

This was about a reincarnation sort of story about Twilight making sombra a normal foal, to gave him a second chance.
He was a weird but calm colt with a curiosity of monsters. There he finds Mara, a manticore that is same sentient as a pony but agressive and very instinctive.
Sombra loves her as a friend, but she has this natural obssesion on him proper of how an animal looks at its mate.
So yep, she thinks sombra is her partner.