What are Vent and Aile?

[Karasai]

Twins?

Siblings?

Secret lovers?

Aliens?

What the hell are they?!

[Fluttershy]

Humans. Neither of them exist at the same time tho. Same with Grey and Ashe. If one exists the other doesn't.Think of it almost as parallel worlds where the only difference is Vent and Ashe exist or Grey and Aile.

[Doogles]

No I think it's established that Grey and Ashe both exist in the same timeline but Vent and Aile are alternates of each other.
Though Grey and Ashe's follow different series of events. Ashe's has Vent and grey's has Aile, most obviously
Though Ashe's storyline assumes that Grey dies fighting that robot from the opening stage, and Grey's storyline just has Grey surviving, and therefore being the one to ride on the train and merge with model A.

[Ryo Hazaki]

No, according to Hideki, Vent and Aile do exist in the same timeline, but in either instance, Giro takes one with him for the delivery and that one gets Model X while the other stays at Giro Express.

Originally Posted by Zan's ZX Timeline

-Vent and Aile both exist together within the universe of the ZX-series. However, there is a case of "same world's different story." In other words, two different stories are told in the world of ZX. In Vent's story, Vent and Aile both work at Girouette Express and by chance Vent is brought along with Girouette starting the events of the first ZX game, Aile is left behind at Girouette Express. In Aile's story, it is exactly the opposite. Vent's story then leads into Ashe's story where she acquires the Model A and Aile's story leads into Grey's Story. Regardless of whose story you are playing, these characters all exist together, all are Chosen Ones that have the potential to be Mega Men and their backstories have all happened. It is just that when Vent is a Mega Man, Aile can't be one. It is the same for the relation between Grey and Ashe, for them their respective intro stages are completed and the split happeneds when one becomes a Mega Man instead of the other. In the cases of an event being reliant on one of these 4 being a Mega Man that event is designated as belonging to either the Vent/Ashe Story or the Aile/Grey Story. However, it should be made clear that an event exclusive to one story probably has a counterpart in the other story. The ZX Anime Commercial proposes a third alternative story, where both Vent and Aile become a MegaMan, this is however not accepted in game canon.

Originally Posted by Hideki, about ZXA's image of Vent and Aile together:

The "Vent part and Aile part" of the game's relation is "The same world's different story." In other words, Vent and Aile both exist at Girouette Express, in the Vent part, by chance Vent is brought along with Girouette and becomes the main character, where as in Aile's part it's the opposite. Therefore, it is not entirely unnatural for both to exist together.

And even if you don't believe the above quotes, ZXA itself blows the whole "Vent and Aile don't exist together" thing apart several times over, the most notable is in one of the Ciphers, it shows both Vent and Aile with the other known Chosen Ones except for Ashe and Grey.

[Fluttershy]

I see, my mistake then. Thank you Ryo. Kinda leaves it open for one or the other to inherit Model Z in a third entry eh? : D

[Ryo Hazaki]

That's what I believe as well. Unfortunately, it seems that Capcom's abandoning Megaman altogether, so we may never know.

Also, to the OP: I believe their relation is that of close friends.

[Wanderer]

Hey wait, are we sure that that picture is proof that they both exist together, or could it just be that Inticreates didn't want to make two different pictures and were cutting corners?

[Doogles]

Originally Posted by Fluttershy

Kinda leaves it open for one or the other to inherit Model Z in a third entry eh? : D

I don't like this idea mostly because of the whole "biomatch" thing
I prefer the concept of each biometal only being compatible with certain people, because why else would Vent and Aile have to use model X as a catalyst to merge with Z, H, P, L, and F

The whole Biomatch thing is something I think they could explore to an extent in a third game. TOO BAD IT'S NEVER GOING TO HAPPEN