Aerndis the teacher is an ancient and hagged magic user, extremely mysterious she is sought out by the Lady Sif so that Sif may learn the berserker incantation.
Aerndis is a Marvel comics character created by Kathryn Immonen and Valerio Schiti. She first appears in Journey into Mystery #646, in the story "Stronger Than Monsters" released in 2013.
Aerndis is a supporting character in the Journey into Mystery series, although so far she appears in both a neutral and antagonistic role.
Major Story Arcs
Stronger Than Monsters
The dragon Nidhogg has instructed Sif of Asgard if she wishes to know the Berserker Incarnation she must seek out Aerndis the Teacher. Sif travels past the Fimbulthul, and past the well Hvergelmir to enter the cave of Aerndis. Aerndis would appear before Sif, in a rush of green smoke and flame, and immediately judge Sif unworthy, striking proud Sif sending the Asgardian reeling. Sif would begin to explain herself before Aerndis speaking of her desire to learn the berserker incantation. Aerndis continues to resist Sif challenging her motivates and wishes, engaging in battle, grabbing Sif by her throat. Sif fights back and persists asserting her desire to become a better and stronger warrior. A fiercer warrior. Her attitude still that of mocking towards Sif, Aerndis would teach Sif the berserker incantation, but patronize her at the end. Sif would appear to lop her head off in an angry dazed blur. Carrying Aerndis head in a bag, it would eventually end up in the hands of Heimdall who would return it to Aerndis body, allowing Aerndis to act of her own accord, readjusted her head, demonstrating she was still alive.
Powers and Abilities
Presumably similar physical traits and powers typical of Asgardian heritage, Aerndis also appears to have great ancient knowledge and wisdom.