Nick (Supernatural)

Nick is a recurring character in the horror series Supernatural, who mostly acts as the vessel to Lucifer. He acts as Lucifer's temporary vessel in season 5 until Lucifer gains his true vessel Sam Winchester, and then returns as Lucifer's full time vessel from season 12 to 13. After Lucifer's demise, he appears as the secondary antagonist (behind Michael) for most of season 14.

He is played by Mark Pellegrino, who mostly portrays Lucifer in the series.

Background
Nick had a wife and baby son, who were one day brutally murdered during a supposed robbery at their home. The incident left Nick deeply traumatised and full of grief.

Season 5
One night he was visited by Lucifer, who took the form of Nick's late wife in order to manipulate him into allowing him to be Lucifer's temporary vessel, and Lucifer put the blame of Nick's family on God. A broken Nick agreed to become Lucifer's vessel, and was subsequently possessed.

Due to not being Lucifer's true vessel, Nick began to burn up and scar overtime due to having to contain Lucifer's essence. After Lucifer's true vessel Sam Winchester consented to Lucifer to use him as a vessel, Lucifer left Nick's body on the floor.

Season 7
When Lucifer began appearing to Sam as hallucinations, he was in the form of Nick.

Season 11
When Dean and Sam went to see Lucifer in Hell in order to try and find out how to defeat The Darkness, Lucifer manifested into the form of Nick when interacting with them. After escaping Hell once again, Lucifer ended up possessing Castiel.

When Crowley went into Castiel's mind, Lucifer appeared to him in the form of Nick and fought with Crowley.

After Lucifer was ripped out of Castiel's vessel by the Darkness, he briefly appeared in the form of Nick.

Season 12
Crowley and his demons found Nick's body, and managed to repair it and began to tweak it to act as a prison for Lucifer. Crowley banished Lucifer into Nick's body in which he was trapped and became Crowley's slave, in revenge for Lucifer using Crowley as a slave before. Whilst imprisoned, Lucifer manipulated some demons to finding a way to break Crowley's spell, and successfully gained back his free will.

Season 13
Lucifer used Nick's body as his vessel for the entirety of the season. During a stand-off with Lucifer, Dean managed to stab him with an archangel blade, which killed Lucifer and left Nick's body on the ground and wounded.

Season 14
It is revealed that Nick survived the stabbing following Lucifer's death, and he resided in Sam and Dean's bunker for three weeks.