My take on what might happen if Garmadon returns in season 8.
Lloyd was on a solo mission to find out more about the "Sons of Garmadon", a mysterious cult in Ninjago City. Xenudah, the main general was running to the base and Lloyd followed him. Within hours, they reached the castle, deep within a volcano. Xenudah stepped forward. A man was standing there with his back turned.
"This ninja here...He claims to be your son." Xenudah said in a low, firm voice.
Lloyd gasped, the man turning around, He wore a black samurai helmet with a mask and black, purple, and green robes. He took off the helmet and Lloyd recognized him in an instant.
"F-FATHER!" He ran forward, collapsing into Garmadon's arms, sobbing. "I-I've missed you so much!
Garmadon could tell that it was Lloyd. "You've grown up so much...How long has it been?"
"Five years." He sobbed on.
His father held him close, stroking his hair in reassurance. "It's okay, Lloyd. I'm right here now."
"But I-I don't understand...why would you send these people to fight against me?"
"I wanted to let you know I was alive. Ever since I returned two years ago, my heart longed to see you again. And I knew that a new evil in Ninjago would always grab your attention."
"WE'RE QUITTING!" Xenudah exclaimed.
"OKAY!" Garmadon called out, before turning back to his son. He giggled softly. "At least we don't have to worry about them."
"I've missed you. So much, Dad..."
"So've I... I'm so proud of you. I mean it. Let's go back to the others. I'm sure they're waiting. Wu's...not here...what happened?"
Lloyd sighed. "He's lost in time. We still can't find him. I've taken charge as master now."
Garmadon was in shock. "Since when?"
"Five years ago, just after he disappeared."
"You've truly matured. I'm very proud."
"I love you so much..."
"I love you too Lloyd. Come on. Let's go."