Marx

Marx is an evil jester and the secondary anatagonist of the Mecha Sonic Saga. He caused the destruction of Popstar, Kirby and Meta Knight's homeworld.

Pre-Mecha Sonic Saga
The sun and the moon were fighting in space above the world of Popstar, which caused the population to panic. Marx went to tell Kirby that the only way toget the Sun and Moon to stop fighting was to get Nova to wish for them to stop fighting. After Meta Knight made a wish from Nova to free Galacta Knight and engage in combat, the two left the area, leaving Kirby to make the wish. It wasn't until Marx showed up and wished for the destruction of Popstar and reveals to Kirby that he got the Sun and Moon to fight. Marx turned into his monster form and defeated Kirby leaving him defeated and weak. Meta Knight found Kirby and brought him to Popstar only to find it getting destroyed.

As Marx was witnessing Popstar's destruction, King Dedede felt the planet shake and saw it get destroyed, his castle getting destoyed as well. Dedede attempted to fight Marx, but was no match for the crazy jester. Marx ends up killing Dedede as a result of trying to fight him. Kirby and Meta Knight then found Marx on the ruined Popstar, but Marx says that's too late to stop him. Marx then opens a portal goes through it and ends up at Mario Circuit, ramming into the races causing the racers to spin out of control. Kirby and Meta Knight were left on Popstar, but luckily Meta Knight teleported them both to Mario's world in time, and Popstar was finally destroyed.