cuz I was too lazy to do it until now xD

So yup if you didn't know Umbra is the evil version/opposite of Neon (which is why their name is Umbra... it's latin for shadow)

Umbra is basically dead, literally, they have no heartbeat nor do they produce warmth. They also experience a lack of emotion and therefore are cold towards most people.

When Umbra gets REALLY REALLY mad they go into what is referred to as 'rage mode' or Rage

When in rage mode, Umbra becomes extremely violent and uncontrollable. Also in rage mode, Umbra just kills, barely ever sparing anyone in the area. That being said, in most cases where people are spared it's because Neon was close to them and instead of killing them they are infected with corruption.

Corruption will alter the mind of the person infected, almost completely turning them to the anti version of themselves. This infection may last anywhere from 10 minutes to several weeks to indefinitely. (to give someone it indefinitely takes a lot of energy and usually causes the person infecting them to fall into a comatose state for a couple of days). The only way to cure this is with a portion of healing, whether that be through a spell or through a potion. The longer the infection was cast for, the more healing required to return the infected to normal.

Umbra's powers include:

Corruption: (stated above) All Umbra needs to do to transfer corruption is make contact with their hand to the skin of the other person.

Mind Manipulation: This ability allows Umbra to manipulate the thoughts of others, does not, however, allow full control of the intended victim. It rather makes them believe that it is their own conscious thought, can be broken with a reminder of reality however.

Void Trap/Nightmare: Causes the victim to go into a comatose state, can be used on a lower scale to induce a state close to sleep but the victim suffers almost constant nightmares. This is caused because their life source (soul?) is stolen, or partially stolen. 

Shadow: Allows Umbra to blend in with dark areas and travel through shadows, however, this uses a lot of energy so is not utilized often.

Along with these Umbra has increased speed, agility, and strength.

Umbra's mentality is somewhat stable, and by that I mean they can still make 'reasonable' decisions but may lose control at times

Likes: The dark, torture (c:), blood, lots and lots of death

Dislikes: loud noises, good people, nice people in general

Hates: BRIGHT LIGHTS, following orders from anyone

idk what else to put so if you have questions, ask away!

Okii cya doods later

[also I thought of an interesting headcannon for Umbra x Scythe, Umbra lacks emotion and is cold-hearted but Scythe 'warms' them up idk xD]