Wumu learned about things in the universe intermittently later on. Pan, Goku, and Trunks, who had become smaller, were three people in a small spaceship running between planets, looking for Dragon Ball, fighting, and being chased by various aliens.
Wumu didn't interfere, and didn't even look at it. He occasionally sensed them, confirmed that they were still alive, and then continued to meditate. Once he sensed that Pan was being chased by a group of monsters on an ice planet. He moved his fingers and wanted to take action, but he held back (She can handle it. She is the granddaughter of Goku.) Sure enough, the next second Pan rounded Power Pole, and the group of monsters dispersed. Wumu took back his senses and smiled.
Another time, Trunks was dueling with an alien on a desert planet. The alien's energy was not strong, but Trunks fought awkwardly - the smaller Goku was not around, and he was not used to it. In the end, Trunks won by himself, and Wumu did not interfere. He told Old Kai that these children have grown up. Old Kai said that it is not them who have grown up, but you who have grown old. Wumu did not refute, he thought the old man was right.
Until the air changed. It was a kind of air that he had never felt before--yin, sticky, like a layer of grease that couldn't be shaken off.
"Here we come." Old Kai put down the tea.
Wumu Open your eyes.
--
GT Timeline, Earth. Baby returned to Earth. He did not come back alone. He followed Pan and the others in the universe, secretly possessing several aliens and sucking their breath. Now he is strong enough.
He landed in Capsule Corporation's yard and possessed first a passing neighbor, then Gohan, then Videl. Gohan's eyes changed color after being possessed, and when he came out he saw Vegeta: "Uncle Vegeta." That smile was not Gohan's.
Vegeta frowned. He felt something was wrong. "You are not Gohan."
"Of course I am Gohan." Baby took a step forward, "Uncle Vegeta, what's wrong with you?"
Vegeta didn't move, and clenched his hands tightly behind his back. The aura on Gohan was wrong, it was not Gohan's aura. "Come out, come out of my nephew's body." He exploded with golden arrogance, Super Saiyan.
Gohan--Baby--smiled, "You are smarter than I thought." The next second, he jumped out of Gohan and jumped on Vegeta. Vegeta wanted to explode and pop the thing out. He went, but the thing was faster than him and got into his pores. He couldn't get away. Baby's breath penetrated like a snake, and Vegeta's eyes slowly turned into another color. He stood up straight and smiled - that smile was something Vegeta would never have.
When Goku and they rushed back from the universe, the earth was no longer right. People on the street were walking, moving very slowly, and their eyes were all the same color. They were possessed by Baby's eggs.
"What the hell..." Trunks landed, his hands shaking.
Pan clutched Power Pole and said nothing. She looked at the people on the street and she didn't recognize them anymore.
Sky Manipulation cracked. Vegeta fell from above. The energy on his body was more than twice as strong as before. Vegeta said, "Kakarot, you are finally back." The voice belonged to Vegeta, but the tone was not.
"You are not Vegeta." Goku said, his eyes changed.
"I am Baby." Vegeta smiled, "In other words, I am Vegeta and I am also Baby. Which one do you want to fight?"
Goku No nonsense, explosive energy. Jin's arrogance rushed forward, Super Saiyan 1, two, three, and finally the hair turned red--Super Saiyan 4.
"Ah--!"
Goku rushed forward and the two collided and fought for half an hour. Baby's Super Saiyan 4 was more stable than Goku's, he had Vegeta's fighting instinct, coupled with his own parasitic energy, punched and punched Goku. Goku was sent flying and hit the mountain. The mountain collapsed. He got up with blood at the corner of his mouth.
"That's all you have?" Baby stood in the air, "You're old, Kakarot."
Goku wiped the corner of his mouth, said nothing, and rushed forward again. This time he hit harder - he knew that a protracted battle would not work, and he had to force Baby out of Vegeta in the shortest possible time. He punched, Baby used Vegeta's stand to catch it, and Goku's punch was pushed to the side; he punched again, Baby turned sideways and pressed his elbow against his ribs. Goku took three steps back, his ribs hurting.
Baby did not chase, but stood in the air with his arms folded. "Did you see it? I used Vegeta's body. If you hit him, he will feel pain. If you don't hit him, I will hit you. How do you choose?"
Goku gritted his teeth. He knew that Baby was telling the truth - he couldn't beat him to death. He was beating Vegeta's body, but Baby could beat him to death. The two of them started again After fighting for a quarter of an hour, Goku's breathing began to become disordered, and Super Saiyan 4 began to shake. Baby punched him in the chest, and Goku flew out and rolled on the ground several times before stopping.
Pan ran over. "Grandpa!"
Goku waved and stood up, his legs shaking. Baby fell from the sky and stood in front of him, looking down at the smaller and scarred opponent. "It's over."
--
Sacred World of the Kai. Wumu is sitting on the grass, sensing. Old Kai is watching him from the side.
"That kid of yours is going to lose." Old Kai said.
Wumu said nothing.
"Baby can't be won head-on. He's attached to Vegeta, and it will hurt if you hit Vegeta Vegeta. If you don't hit him, he will hit you." Old Kai glanced at him, "When do you plan to move?"
Wumu picked up the tea cup, the tea was cold. "Wait until he is about to kill him."
Old Kai snorted and picked up the little book again, "You martial arts practitioners all have the same problem. You have to see someone dying before you take action."
Wumu didn't answer and took a sip of herbal tea. (He wasn't watching a show. He was waiting for that point, when his punch would be effective. Too early Goku won't learn, too late and there will be no one left.)
He put down the tea cup and stood up. "Let's go."
"So fast?" Old Kai raised his eyes.
"It's time."