Once there was you, me, and us (Sinister Strange x fem!reader)

After (Y/N) and Doctor Strange are banished to his incursion-stricken universe by the Scarlet Witch, they meet an alternate version of Stephen, corrupted by the Darkhold. In desperate need to find a way back to stop the Scarlet Witch, the heroes are faced with yet another challenge: Sinister Strange's obsession for (Y/N).