User blog:Crosaffcheg/The greatest cameo ever

So Stephen Amell just announced on his Twitter account that Season Finale of Arrow will feature unexpected cameo which was never shown or told about.

Who do you think it's going to be?

My personal thoughts, this is Roy Harper. He was announced in Season 5 last summer and it was surprising not to see him the whole season. Probably they just kept him until the end.