Chronos

Chronos was the Greek god of Time. He went under the alias Ethan Snider.

Powers & Abilities
As a Pagan Deity, Chronos was very powerful, however, even for deities, he was strong, much stronger than most deities, as such, he possessed several incredible and rare powers.
 * Time Travel - Chronos is the God of Time, thus he can travel through time, either backwards or forwards. He can take others along with him, if he so chooses. However, he will travel any way, if summoned. If Chronos doesn't maintain enough power, he will be "catapulted" back to the present.
 * Foresight - He can see the future and used this ability to rake in money to live on.
 * Immortality - As a deity, Chronos doesn't age.
 * Superhuman Strength - Chronos was strong, inhumanly strong, able to causally over-power humans.
 * Superhuman stamina - He never tires, regardless of what he had been through.
 * Invulnerability - Few things could damage him, he barely reacted to punches in the face, and took two bullets in the back, and didn't even react.
 * Time Manipulation - As God of Time, Chronos has the power to control time and disrupt the flow of it, causing objects that measured time to stop permanently, much like Reapers.
 * Life-Force Absorbing - Chronos used the life-force of mortals to power up and maintain his powers.
 * Teleportation - Time jumps or not, he is able to disappear and appear in a completely different place in the blink of eye.
 * Superhuman Intelligence - Being thousands of years old and a god, he possesses vast knowledge about the world and its workings.

Vulnerabilties
Chronos can be killed by being stabbed in the heart with a thousand year old branch of an olive tree covered in the blood of an unknown source.

Early Life
When he was worshiped he gained his power from taking time from his worshipers. No longer worshiped, Chronos was forced to feed after a couple decades on three Humans to stop wandering time. He eventually met a human woman, Lila Taylor and fell in love with her. Although he didn't tell Lila who he really was, he was forced to kill in order to return to her. His powers sent him into the future so he needed power to return.

Season 7
On his last feeding in 2012, he is tackled by Dean, and Chronos takes both of them back to 1944. Dean was arrested almost immediately. Chronos intended to get rid of Dean but found that Dean was released by Eliot Ness. So when he notices that Eliot is lurking about he attacks, but doesn't finish Eliot off due to a moment of distraction. Later Dean breaks in and the two fight, but are stopped when Eliot takes Lila hostage. Chronos begins to choke Dean, but is summoned back to 2012 where he faces Sam. He lets go of Dean and fights Sam. Chronos is stabbed in the heart by the stake and, as he dies, gives them his final premonition by telling them their future is full of black goo.