Arrow co-creator and showrunner Marc Guggenheim recently posted an alternate opening for the season 1 finale, "Sacrifice."
Guggenheim noted that the sequence was cut for time, but eventually wound up in the Season 8 finale, "Fadeout."
The scene flashes back to Oliver Queen (Stephen Amell)'s final moments with his father Robert (Jamey Sheridan), where Robert urges his son to survive before turning a gun on himself. It then cuts to Oliver being doused with cold water, as he comes face to face with Malcolm Merlyn (John Barrowman).
"Sacrifice" focused on Oliver's battle with Merlyn to stop the Glades, the lower class section of Starling City, from being leveled by an earthquake machine. Oliver beat Merlyn, but a second earthquake machine was triggered, leading to the death of Merlyn's son Tommy (Colin Donnell), who was also Oliver's best friend.
Arrow stars Stephen Amell as Oliver Queen, David Ramsey as John Diggle, Rick Gonzalez as Wild Dog, Juliana Harkavy as Black Canary, Katie Cassidy as Black Siren, Katherine McNamara as Mia Smoak, Joseph David-Jones as Connor Hawke and Ben Lewis as William Clayton-Queen. All eight seasons are currently streaming on Netflix.