who is he
My responses to the first post:
1. Spot at the end of the PokeDex
BW organized their PokeDex rather nicely and, for the most part, had the Pokemon ordered in approximately the order you would find them in the wild. It only makes sense for Volcarona to be placed after Hydreigon--you can catch Deino in Victory Road but you have to wait until post-game to catch Volcarona.
Volcarona, meet Unown.
3. Relic Castle and the Encounter
Volcarona had an entire floor to itself, Unown had an entire area.
Setting Unown aside for a moment, though, I'd like to mention Rotom; not a legendary, not a pseudo-legendary, but the Old Chateau was pretty much designed for it. You went in there, saw some ghosts with a possible relation to Charon, got the Old Gateau, and caught Rotom (with a definite relation to Charon).
I can't deny that this is an interesting piece of information; however, the reason behind denying Volcarona the ability to infatuate could simply be one of gameplay fairness. Or it could have simply been designed as a genderless Pokemon originally. Nothing legendary about that; just ask Magnemite.
I don't think Volcarona was designed as a legendary originally; perhaps a pseudo-legendary, but to be honest I see nothing odd about giving some focus to a super-cool non-legendary in-game. We have non-legendary event Pokemon now--Volcarona can do what legends do without being one! He's just that great.