Nickname referring to Kira Yamato of the anime series' Mobile Suit Gundam SEED and Mobile suit Gundam SEED Destiny; particularly the latter.
The reason being that Kira Yamato as the main protagonist for most of Destiny was omnipotent. Kira would fly into any ongoing battle with his Mobile Suit (Robot) Freedom Gundam and own every other unit. Along with many other plot and design flaws of the series, Jesus Yamato's onesidedness made the series unwatchable for many.
Who is the best Gundam pilot?
A: Kira Yamato hands down.
B: Another vote for Jesus Yamato you gundam seedlings - my vote's for Amuro Ray!