Avengers (1963) #378

Avengers Magdalene, Swordsman, Vision, and Deathcry, arrive in Scotland to check on a remote tracking station. While there, the Avengers encounter a disgraced Shi'ar warrior, and fall under the influence of the Mephisitoid! Who is the Mephisitoid? And will the team be able to escape its mind-altering powers?