Somnambula

Somnambula is a female Equestrian Pegasus and figure of Equestrian legend first mentioned in Season six's The Crystalling - Part 2 as the one subject to a spell called 'Somnambula's Weather Abjuration', as well as the one for 'Tempus Objectus'. She makes her first physical appearance in Daring Done? to where she rescued her father, Prince Hisan, from a sphinx, and she also appears in the IDW comics' My Little Pony: Legends of Magic Issue #5 as one of the top figures introduced in both the comic franchise and Season 7, in the comic saving her home from a giant snake.

Role in the series
She presumably died of old age by the time of the series, and thus this allows the sphinx, named Egyptia, to return as she felt she was no longer bound to the terms of Somnambula's triumph, as Egyptia was reportedly the last of her kind since they enslaved ponies to worship a Mothron named Pharaoh Plague. It's also revealed that her Tempus Objectus spell was used by Grogar and Baphomet as a way to awaken Darkspawn artifacts and to banish anyone who opposes them into the Banished Realms.