There have been all kinds of theories on who the Clairvoyant is. Guesses include the Leader, Modok, the Scarlet Witch, Alexander Pierce, or even Obadiah Stane's son, Ezekiel Stane. Out of those guesses, I'd say Modok is the best guess.
But my idea is something completley different, and somewhat crazier. On the Marvel side of things, everyone is always arguing if the Fox's X-Men/FF and Sony's Spider-Man should be included in the MCU. On the DC side of things, everyones always arguing whether or not the "Arrowverse" should be included in the unofficial DCCU. And don't even get me started on TDK trilogy.
But what if both companies are playing off something even riskier? What if Marvel Studies and Warner Bros are working together to create the multiverse, explored in the comics years ago?
Ladies and gentleman, my Clairvoyant guess is none other than Robert Queen.
Now, I'm sure your scratching your heads and thinking I'm a troll right now. But hear me out!!
In the TV show Arrow, Robert Queen is Oliver Queen's dad. They go on a cruise together and the ship sinks. Robert and Ollie are the lone survivors on a small boat. There is only enough water for one person, so Robert shoots himself so that Oliver will survive.
On the show Supernatural--which is viewed on the same channel as Arrow--there is 1835 Colt Paterson revolver, which will kill anything shot by it, "including creatures normally immune to any and all weapons." Needless to say this a magical gun. What if for the premise of Arrow they have another magical gun, one the Queens didn't know was magical. This gun is the gun Robert Queen used to shoot himself with, and this bullet didn't actually kill him but transferred him to another reality.
Even if there is a body left in the "Arrowverse" they could still put Robert Queen's consciousness in another persons body or simply copy his original one. This would take the audience by complete surprise, as well as doing something never done before on television.
So what do you think? Let me know in the comment section below!