Uriel

"I didn't see that coming"

-Uriel, after Lucifer, stabs him

Uriel was an angel and one of Lucifer's siblings. He was a member of the Heavenly Hosts and welcomed souls into the city of Heaven. He eventually went rogue and tried to kill Chloe Decker and his mother, but was killed and eradicated from Creation by Lucifer.

History
Uriel was one of the middle-born angels. He was a small child and always wanted to play with Lucifer and his older siblings. However, they excluded him. Since then, he has grown, but he remained subordinate to his elder siblings. His duties include welcoming the souls of deceased, righteous mortals through a speech, which Lucifer describes as being "worse than Hell".

Uriel ventured to Earth in an attempt to eradicate Goddess from existence by using Azrael's Blade. However, his plan failed when Lucifer killed him with the blade. It was revealed that Uriel's last words were, "The piece is here."

Powers & Weaknesses

 * Angel Physiology: As an angel, Uriel has their physiology, including superhuman strength, speed, stamina, durability, endurance, agility, reflexes, resilience, senses, and intelligence, immortality, invulnerability, eternal lifespan, regenerative healing factor, flight, shape-shifting (being able to hide his wings). As well as their weaknesses.
 * Nigh-Omniscience: Uriel is a master strategist and has a supernatural understanding of patterns and their consequences. With a slight movement or adjustment to a surrounding object, he can set forth a sequence of events.
 * Master Martial Artist and Hand to Hand Combatant: Despite Uriel's smaller size, he is a very capable fighter. He utilized his ability to notice and recognize patterns in his fight with Lucifer and Mazikeen, winning the fight until Lucifer caught him with a surprise attack and killed him using Azrael's blade.

Personality
According to Goddess, "Uriel is a stubborn boy. When he sets his mind, it doesn't waver." Growing up, Uriel looked up to his elder siblings. He kept trying to play with them no matter how many times they excluded him. He is obedient and a little frightened of his eldest brother, Amenadiel. However, when he realized that Amenadiel is weakened, he took pleasure in knocking Amenadiel over and beating him up.

When he came to Earth, Uriel was quite arrogant, murderous, and sadistic, having no qualms about killing his mother or Chloe Decker.

Trivia

 * Uriel is an archangel in many traditions, though to many beings he has no reason to have this rank.
 * Uriel is the first being that Lucifer has ever killed.
 * Uriel was acting on his own, not on God's order.
 * Uriel was killed by the Flamming Sword, meaning his soul was destroyed and purged from existence so he can never return.