Just how would the guys become a giant. Would a mysterious demon with 10+ more tails curse them or would they perform a new giant jutsu that makes one gigantic and never wears off even with little chakra left.(And only the jutsu user can decide to shrink back to normal.) And at this size their chakra is 10,000x the original chakra.

Would it be through a cursed scroll that turns all who looks upon it into giants and granting eternal youth and life.