According to a really old prophecy it has told that Gumball Watterson was destined to become the Ultimate Hero. It was told that the Ultimate Hero would have the power of every master in the entire planet.
Sensei Wu taught him the ways of Spinjitsu.
He helped Lloyd learn everything he needs to learn on how to become the Green Ninja.
He trained him until he found out that he was fully trained
He's currently training her