Guys, the beloved Oliver Queen a.k.a The Arrow will live to see another whole season. This poster shortly released confirms the existence of the Lazarus Pit which is basically a pit filled with a pool of magical liquid that can heal the wounded and the recently deceased, like Oliver. Although it may have side affects, Oliver is coming back and that's all that matters.
Possible Effects of the Lazarus Pit existing in the Arrow and Flash Universe:
As the poster reveals, the pit will be a green color, which could just be the end of it, but I think (and some references from the comic books point in this direction) Oliver will not remain The Arrow anymore but will turn into The Green Arrow, who turns into a Ra's Al Ghul-level warrior. He could be much stronger, maybe mirakuru-level without the side effects, and he could even be immortal, but that's highly unlikely. All I know is this will bring a change in The Arrow physically and mentally. After all, he does have to beat Ra's in the end.
This could mean that[The Flash](series:1068303) will no longer have the 'super' or 'metahuman' advantage over The Arrow, as was portrayed in the crossovers. Oliver may have enhanced abilities and aftereffects from the pit, as Ra's seems to have. Remember, the writers have the freedom to do anything they want with the show so if you see The Arrow as a super human later on in the season don't be too shocked. And for all you Flash vs. Arrow fans, remember technically in my viewpoint Arrow basically beat The Flash: Remember how Oliver holds Barry by the neck to bring Barry back to his true self? Oliver could have easily killed, paralyzed or done anything to the super Flash, as he couldn't run and escape the hold. So that does mean Arrow won in a way. Oliver never went down badly, even with super speedy punches coming his way. The possibility of Oliver going near or completely "super" may lead to GREEN ARROW vs. THE FLASH next time around where an actual winner could be shown, though it's highly unlikely the producers would let either lose.
So guys, I think we will be seeing the [Arrow](series:720988) turn into the classic name "Green Arrow." He will for sure reveal himself to Starling City with an Arrow symbol or a sign for Detective Lance (Batman and Commissioner Gordon style). After all Oliver Queen is going to need super strength and enhanced capabilities to keep his ground in the super universe he lives in.