Constanqueen

Constarrow is the slash ship between Oliver Queen and John Constantine from Arrow.

Canon
2010

While secretly stationed as a spy on Amanda Waller's orders at Lian Yu, a returning Oliver learns that his camp is looking for something other than slave labour for their drug trade. Their leader is searching for something mystical and when Oliver's sent on a one of the search missions, he happens upon Constantine, who takes him hostage and brings him into the 'cave of wonders' where the mystical artefact is located.

Fandom
AO3