Xar was the wannabe leader who wanted to bring everyone to victory, even though he wasn't too good at it. He's a typical green color, however slightly darker than usual. Most of the time, he wears a blue sweater similar to the one Kirby wears with the Freeze or Ice Climbers ability. His favorite ability is sword, because his ability gives him two of them, as well as the ability to spit out new ones at will. His other ability scrolls were of Hammer, granting him the giant hammer attack and the ability to shoot needles out of the hammer, and the light ability scroll, which increased it's power and allowed it to function similar to the laser ability. His skill scroll contained the ability to control machines, however he wasn't very good at using it. He's slightly under average intelligence, often making deadly mistakes but can occasionally come up with a decent plan.
Significant things Xar did during Project Dark Star were getting the Sword, Hammer, and Light ability scrolls after being thrown into the blue portal by Tharuk, telling all of the clones to meet at the meteor Dark Star and lead them into the red portal, took down Dedede's giant castle with his machine-controlling scroll, and fighting Marx with the Rainbow sword.
In Mirror World Rescue he didn't do much until he destroyed Mecha Kracko with his machine scroll. However, due to the impaired effectiveness of his clairvoyance scroll, Voyant thought that Mecha Kracko was a long ways off, when in reality it was directly above them. The giant robot fell on top of Xar, killing him instantly. Later on, Tharuk salvaged Xar from the mass of metal that was launched into space by one of the other clones, and used Xar's skill scroll and his newly acquired robot sidekick Tharbot to replace all of Xar's damaged body parts with machines, forming a robot-cyborg-zombie. Xar piloted Tharuk's house, which turned into a robot and used faerie magic gem things to teleport into the mirror world, and waged war against a giant warship named the Serapis, which was being operated by Tharuk's mirror world double, Kurath. The house was destroyed but Xar managed to infiltrate the Serapis and free Tharuk, but unfortunately while Ayumu was destroying the ship in an attempt on Tharuk's life, Xar was badly burned.In Candy Constellation Xar was healed, repaired, and turned back to the side of good to aid the clones as a cool cyborg.