[quote=Kaga]
Yeeeaaaah he only* ever used that ability when he was being controlled, so I don't see him summoning that power on his own. Too dangerous. *Not counting his final battle with Knives, but in that case, no one else was around, so...
[/quote]

Honestly, my personal knowledge is 'until he did that'. So, just after Legato showed up. Haven't read the manga, never finished the anime. But... I know what Vash [i]is[/i] and can do. XD