Have Piccolo Jr. train under Mr. Popo alongside Goku, Yamcha, Krillin, and Puar. With Piccolo Jr.'s growth rate, he would quickly catch up to Goku's current progress, but defeating Goku was already impossible.
Goku, Yamcha, Krillin, and Puar had already gained an initial grasp of the Ultimate Qi Training Technique, Eightfold Transformation Technique, and Sole Self, Myriad Phenomena Technique taught by He-El. After being tempered through battle with King Piccolo, they had come to understand themselves and were entering a stage of rapidly increasing their combat strength.
Although Piccolo Jr.'s growth rate was fast, in the original story, he had merely taken three years after the old King Piccolo's death to grow into an adult. In the end, he lost to Goku by only a single move. His talent surpassed that of the old King Piccolo, making him a genius among geniuses.
Even among the Namekians on Namek, Piccolo was one of the most exceptionally gifted at the very top.
However, now that he had encountered Goku, who practiced the Ultimate Qi Training Technique taught by He-El—especially a Goku who had already begun to grasp it and entered a period of rapid advancement—it would be difficult for him to catch up.
He-El had not tailored any martial art specifically for Piccolo Jr.
Of course, if Piccolo Jr. were willing to set aside his arrogant attitude and possessed the same character as Goku, Yamcha, and Krillin, He-El would not mind creating a martial art exclusively for Namekians.
But for now, his temperament was still lacking.
After tossing Piccolo Jr. to Mr. Popo for training, He-El did not concern himself with him further.
He-El had his own matters to attend to.
"You want to remove the entry limit on the Hyperbolic Time Chamber?" Kami frowned when he learned of He-El's plan.
The