With Roy Harper now technically dead to the entire world outside of Team Arrow and The Atom, the Arrow, or at least the Arrow we knew, is over. No longer being capable of continuing forward as the Arrow and left with nothing but his dead sister, Oliver Queen has taken his rightful place as heir to the demon, or Al Sa-him. He has now donned the full league of assassins attire, wielding a black quiver, black arrows and the blade of Ra's Al Ghul itself. But after three seasons of evolving from a man to a legend, can Roy Harper really just go away forever? To answer that, we need to reexamine his journey so far.
Roy Harper's evolution from street thug to a mirikuru enhanced super soldier who murdered an innocent police officer. But his true evolution came in season 3 of Arrow. Roy showed his true colors (which just so happen to be crimson and black) as he joined Oliver's crusade under the alias Arsenal, a name given to him by Oliver after Arsenal defeats Wildcat Grant's old apprentice who went rogue. And as the season continued, we really get to see there's more to Roy than just a mask. In fact, his mask may have very well been what he was hiding behind. Guilt-ridden over murdering an innocent officer, Roy's subconscious translated the fractured, but not forgotten, memories into him killing Sara Lance. We know now that Thea killed her under the influence of Malcom Merlyn, but that doesn't ease the pain residing in Roy's heart. He continues to walk side-by-side with Oliver and the gang into battle in attempt to atone for his sins, which he confesses to Thea, Oliver and Quentin Lance during his arrest and time in jail for "being the Arrow". This was a rouse, as Roy was simply buying time in there till Diggle's associate could get to him, and all so Oliver could end this war with Ra's Al Ghul. And his sacrifice isn't easy. He gets jumped and stabbed by prisoners only to be fake-killed by a prison guard (who was actually Diggle's associate). These events led to Roy being forced to leave Starling City behind him, as the public thinks he is dead. But in Roy dying, so did the Arrow, and Arsenal. We know Oliver has become Al Sa-Him, heir to the demon. But what about Roy?
For starters, Roy has one more episode in Arrow season 3 in which he will return to Starling City, so we may find out some clues to his new whereabouts there. Personally, between his training under Oliver and time as Arsenal, as well as basically not having an identity anymore, there is no other direction I can see him going then to save the world somewhere new. And with one character having been confirmed to be bouncing between Arrow, The Flash and the Arrow/Flash spin off, my money is on Roy. He went to Bloodhaven in season 2, which comic fans will instantly recognize as the battleground for Night Wing's heroics, so he may have made some "super friends" there. Also, Ray is the main character of the spin off show, and with the heroes pretty solidified in Arrow and The Flash (for now), I can't see why any other member would be the nomad of the group except Roy. Using Ray as a resource to get a new identity and his technology to find threats all over the globe, Roy could easily gather intel for Ray and the other heroes on these impending threats. He spent the majority of season 2 gathering intel for Oliver, right? Again, these are just my thoughts, but the way things are shaping up all signs from my end point to Roy becoming the character that interacts with all three shows, acting as a nomad or intelligence gather for future or possible threats, or even finding and training new heroes. Ray does seem to have some new faces in his spin off line up, and judging by how he fought deathbolt, he'll definitely need Roy to teach hand-to-hand combat, survival instincts, stealth and more.
Also remember the conversation between Cisco and Ray right after Ray name's the meta-human deathbolt? They uncover that deathbolt was not in Starling City the night the particle accelerator exploded, leaving only two explanations; First, the dark matter that leaked into our atmosphere could be spreading beyond Central City, creating essentially a sort of epidemic, but instead of a cold you get some crazy super powers. The second explanation is that deathbolt's powers derive from an entirely different source than the particle accelerator explosion. Bringing in Super Girl and Titans, alongside the spin off series, his powers could be connected to any one of their universes as well. But either way, I strongly feel that Ray's spin off show will heavily feature Arsenal. Why? Because Ray is facing the unknown; he's out of his depth. He knows science, but Roy knows hot to fight, survive, infiltrate and execute. Those skills will be crucial in either scenario to Ray. Training the newbies, gathering intelligence, tracking new enemies, rendezvousing the other heroes together when need be. It all adds up when you look at it. Ray needed Oliver to fight with his suit because he himself did not possess that 'killer instinct'. Recognizing this weakness, it would only be logical for Ray to recruit Arsenal to his team. So there you have it folks. Roy is my candidate for this mysterious character jumping between all three shows and interconnecting story lines. Whether that be as a hero, a spy, or a trainer, I cannot say. But one thing's for sure - you don't bring in a character as monumental to the franchise as Arsenal and just have him disappear. He will be back. He has to be back. Every team needs an Arsenal, after all.