Asgard's leading warrior, who was Thor's friend long before he was anybody's hero.
Sif is Thor’s childhood friend and the best fighter in the room in most rooms she is in. The films give her less than that deserves, and what they do give her is consistent: she is the one who tells him the thing he does not want to hear, and she is still standing there afterwards.
Jaimie Alexander plays her across eleven years and five projects, which is more than most of the Asgardian court manages, and the two appearances in Agents of S.H.I.E.L.D. are the moments where the television side of this catalogue gets to touch the cosmic one.