Music Meister (CW)
Real name: Unknown
Full name: Unknown
Aliases: Music Meister
Alter egos: Abra Kadabra (CW), Alpha, Bane (Dark Knight), Bane (new 52), Batman (Bane), Billy Numerous, Copperhead, Darklight, Desaad, Doctor Occult, El Dorado, Fun Haus (BTBATB), Gentry, Gluttony, Inque, Jack, Joker (DCEU), Midnighter, Mister Mind, Mister Mxyzptlk (CW), Prometheus, Ra's Al Ghul (CW), Red X, Sea King, Shim'Tar, Silver Monkey, The Joker (Dark Knight), The Music Meister, Weather Wizard
Creator: DC Comics
Alignment: Neutral
First appearance: Supergirl Season 2: Episode 16
Occupation: Interdimensional Do-gooder, Author
Gender: Male
Height: 5'8" • 173 cm
Weight: 152 lb • 68 kg
Eye color: Brown
Hair color: Brown
Superpowers: Hypnokinesis, Intelligence, Omniscient, Power Absorption, Teleportation
Stats: intelligence 100, strength 10, speed 25, durability 20, power 100, combat 60

History:
"Music Meister" is an extra-dimensional being with unexplained supernatural powers and an author in an erased timeline. He claims to originate from somewhere outside of the normal universes of the multiverse, which he describes as being beyond the comprehension of ordinary humans.

Powers:
 Music Meister has the ability to hypnotize anyone he makes eye-contact with, sending their minds into a dream world. He is also able to enter the dreams and manipulate the dream world as he sees fit, including the "free will" of the dream people within it. While only existing in the person's mind, if they are to die in the dream, they will die for real, or at least that is what he claimed.  Anyone under the effects of his hypnosis becomes energy-linked to him, enabling him to gradually steal their powers for his own usage. He is also shown able to contain and draw power from multiple targets at once (i.e. Supergirl and The Flash).  Claiming to be aware of everything, Music Meister has indeed shown to have in-depth knowledge of various places and people from across the multiverse. Despite coming from an unknown reality he was aware of the existence of Earth-1 and Earth-38, along with detailed knowledge of the secret identities and personal lives of Barry Allen as the Flash, and Kara Danvers as Supergirl.  Music Meister is able to teleport, enabling him to easily escape a meta-human cell. To observers, it appears as if he becomes translucent and fades out of existence. However, he apparently cannot travel between different universes in the multiverse on his own, requiring the usage of Kara's interdimensional extrapolator to do so. Alternately, it's possible that he may be capable of traveling between dimensions on his own, but simply used the interdimensional extrapolator for the sake of convenience.   While linked to Supergirl, Music Meister possessed her superhuman durability, strength, speed, heat vision, and flight. With her powers, he was even fast enough to easily catch both the Flash (whom can reach velocities of at least Mach 13.2) and Kid Flash (whom can reach velocities of at least Mach 3).  While connected to the Flash, Music Meister also possessed his Speed Force connection, giving him another method of achieving super speed. However, whether Music Meister can combine Supergirl and the Flash's speeds is currently unknown, as the former's source of super speed is solar energy absorption while the latter's source is the Speed Force.   Music Meister has a talent for sleight-of-hand, able to easily escape from high-tech cuffs. He also, through unspecified means, was able to escape a meta-human-proof cell in the S.T.A.R. Labs particle accelerator.  Music Meister is also a talented dancer, as he is shown dancing when performing "Put a Little Love in Your Heart".  Music Meister is shown to be a clever and crafty individual. Feigning capture, he was able to get close enough to Supergirl to use his powers on her and use her interdimensional extrapolator to escape to Earth-1.  In addition to his love of music, Music Meister has shown a talent for singing himself.