Sully

Sully is a zanna and was the imaginary friend to a young Sam, and later Reese and her sister Audrey.

Background
Sully was Sam protector, when Sam is 9 years old. He always accompany him until Sam later rejected and leaved him. He later moved on from Sam with severe heartbreak.

At some point after Sam's leaving, Reese and her twin sister Audrey was a child that protected by Sully in the past. However all become wrong, when an accident involving Sully and her twin sister, Audrey, caused her death. The accident was so terrible, and caused her developed serious trauma. She later developed a serious obsession of invisible man and later with folklores. After the accident, Sully also developed severe trauma that make him cannot approach children simply for many years.

Season 11
After many of his fellow Zanna and friends killed, he able to locate Sam and later teleported to The Men-of-Letters Bunker. He beg to Sam and Dean to help him to deal with his friends killer. After Sparkle and Nicki killed, he got distress signal from Weems and located him. When he and Dean looking for some medicine and bandage to patch Weems up, Weems revealed to Sam if Sully was falling into severe heartbreak after rejected by Sam.

Sam later give apologize to Sully about what happenend in past, and later tell him about the release of The Darkness, which Sully has aware before and promised to fix it all. However Sam has no gut to enter the Lucifer's Cage. Sully later encourage him to did it. After Reese capture Dean and luring Sam and Sully to the warehouse with a text from Dean's phone, and revealed all of what she experienced,  Sam, Sully, and Dean talked her down, she had change of heart, and make her abandoned her obsession. After the problem solved, Sully later moved on from Sam for once more.

Powers and Abilities

 * Invisibility - He is invisible to humans unless he allowed a human to see them.
 * Telepathy - He mentally connected with each other.
 * Teleportation - He able to teleport into the Men of Letters bunker. It's very unique, because the bunker itself is magically warded, and he able to bypass it.
 * Magic - He had a limited range of magical powers typically passive in nature including conjuration, empathic sensing, and glamouring.
 * Reality Warping - Sully never aged, even years after his encounter and Sam leaving.

Weaknesses

 * Magic - Although invisible to humans, a spell could be cast to allow humans to see Him.
 * Zanna-killing knife - He capable to be killed with it.

Appearance

 * Season 11
 * Just My Imagination