Angelo

Season 1

Angelo becomes Damon's guardian angel. He helps Damon heal from his pain and past scars. He wishes for Damon to love himself and build up his will to live. Even though he shouldn't, Angelo falls in love with him.

Before becoming an angel, Angelo was a human too. He had a boyfriend with whom he loved very much. On the night he died, he was on his way to his boyfriend's concert to propose to him and let the world know about their relationship, but before that could happen, he got into a car accident and passed away. At his burial, he saw his boyfriend with another man.

Angelo suffers when he sees Damon in pain. He can't handle seeing the man he loves in pain, so he uses his powers to relieve Damon of his pain even when he is not supposed to. When Damon finally accepts his fate and decides to live the rest of his days in peace, Angelo prepares to ascend. They say their goodbyes and Angelo surpasses.

A few months later, Angelo reunites with Damon after Damon passes away.

Season 2

Angelo is assigned to another human as their guardian angel, for he has yet to fully learn what God is trying to teach him. His new charge is none other than Anthony, Damon's ex-boyfriend.

While trying to complete his new obligation, a dark truth is revealed about Angelo's past and the secret behind his death. When he was still alive and dating his boyfriend, Kevin, he was not yet ready to tell others of their relationship, which in turn pained Kevin. Because of this, Kevin felt unloved and found someone new. Kevin then admits that he hired someone to tamper with Angelo's car brakes, so he would purposely get into an accident and die. Upon hearing this piece of news, Angelo feels heartbroken and betrayed.

During this revelation, Angelo reveals that he already knew about Kevin's infidelity even before his burial. He wanted revenge on Kevin by killing Anthony, Kevin's other lover. But on his search, he could not locate Anthony and found out about Damon instead. Knowing that Anthony would be hurt if something happened to Damon, he hired someone to rape Damon. Filled with guilt, Angelo breaks down for getting Damon involved in his revenge plan. He blames himself for Damon's death and hurting the person he loves. If he wouldn't have hired that man to rape Damon, then Damon would have never contracted HIV and passed away. Kevin tries to console him to no avail.

Later, Angelo is confronted by Damon who accuses him of killing him. He breaks down again, apologizing and begging for forgiveness. After Damon questions his love, Angelo tells Damon that he does love him and would even die again to pay for his sins. Damon leaves unable to forgive him.

Drowning in his guilt and heartbreak, Angelo starts to become consumed by darkness, even when God had warned him multiple times to control his emotions. Right as he is about to be taken by Satan, Damon shows up and forgives him. They both make up with each other before ascending to Heaven.

(Source: MyDramaList)