Officer Daily is a corrupt police officer who is loyal to The Church of Blood and secretly worked for Brother Blood as his right hand man.
The Church of Blood
Daily worked for the Starling City Police Department and did many things for Brother Blood such as pulling Laurel Lance over for a DUI and informing his second employer Captain Quentin Lance about it. Daily helped Brother Blood kidnap a crime lord known as The Mayor, however he was stopped by Arrow and Black Canary. Brother Blood tested The Miracle Super Soldier Serum on The mayor, however the test failed.
When Brother Blood watched a news report of Green Arrow killing Count Vertigo, Daily reported to him there was success with one of The Miracle Super Soldier Serum test subjects who a man named Cyrus Gold. After what happened to Cyrus Gold, Daily returned to the police station and learned Roy Harper, Thea Queen, and Sin were looking into the death of Max Stanton (one of the failed test subjects to The Miracle Super Soldier Serum).
Daily reported this to Brother Blood and prevented the three from finding out what they needed to know. Daily overheard Quentin Lance and Lucas Hilton preparing a police squadron to take down Cyrus Gold and offered to help before he warned Brother Blood of what was happening. During the raid, Cyrus Gold injured Daily.
Daily ran into Quentin Lance at the police station to ask him how his injuries were after battle, however Assistant District Attorney Laurel Lance interrupted the two allowing Daily to get away.
Daily trashed Laurel's apartment to stop Laurel from finding information about Brother Blood and found unsubscribed drugs allowing him to arrest her. Daily kidnapped Laurel after her arrest and pretended to be Brother Blood while luring the Arrow in. When the Arrow showed up he defeated him and had him at gunpoint. However, Laurel Lance then shot the crooked cop in the chest killing him.
Believing in Sebastian Blood's cause, Daily died while wearing the mask of Brother Blood. After his death, Laurel and Team Arrow no longer suspected Sebastian and believed the threat was over. This allowed Sebastian and Slade Wilson to complete their scheme.
Daily was highly skilled in close combat. Unarmed he was able to defeat the Arrow while the latter used his bow as a melee weapon.
Daily was also highly skilled in stealth, moving around without getting noticed. He was able to completely suprise The Arrow. Daily was also somehow able to disappear in the blink of an eye and appear behind his victims.