Names：

Ace Killer

（Mebius Killer）（Victory Killer）
Status： Extradimensional Terrible-Being
Tags： Alien Civilization
Old Enemy： Ultraman Ace
World： the World of Ultramen
LeveL： S

Ace Killer was a creation of Yapool in an attempt to kill Ultraman Ace. By luring the Ultra Brothers onto a desolate planet and forcing Ultraman Ace to battle the Terrible-Monster, Baraba on Earth. Ace Killer was released and absorbed the powers and weapons of the Ultra Brothers. With their power, Yapool released a robot replica of Ultraman Ace to demonstrate Ace Killer's power. Withstanding a Metalium Beam, Ace Killer used a barrage of Ultraseven's Emerium Beam and Ultraman's Spacium Beam to weaken the robot until it destroyed it with a variation of Zoffy's M87 Beam.

Eventually, Ultraman Ace returned to try and rescue his brothers but was ambushed by the powered-up Ace Killer. With the Ultra Brothers' powers, Ace Killer easily overpowered Ultraman Ace until the Ultra Brothers used the last of their energy to replenish Ultraman Ace. With their combined energy, Ultraman Ace hurled a concentrated ball of their energy (the attack known as Space Q) at Ace Killer, destroying Yapool's weapon against him and releasing his comrades.

Ace Killer was a creation of Yapool in an attempt to kill Ultraman Ace. By luring the Ultra Brothers onto a desolate planet and forcing Ultraman Ace to battle the Terrible-Monster, Baraba on Earth. Ace Killer was released and absorbed the powers and weapons of the Ultra Brothers. With their power, Yapool released a robot replica of Ultraman Ace to demonstrate Ace Killer's power. Withstanding a Metalium Beam, Ace Killer used a barrage of Ultraseven's Emerium Beam and Ultraman's Spacium Beam to weaken the robot until it destroyed it with a variation of Zoffy's M87 Beam.

Eventually, Ultraman Ace returned to try and rescue his brothers but was ambushed by the powered-up Ace Killer. With the Ultra Brothers' powers, Ace Killer easily overpowered Ultraman Ace until the Ultra Brothers used the last of their energy to replenish Ultraman Ace. With their combined energy, Ultraman Ace hurled a concentrated ball of their energy (the attack known as Space Q) at Ace Killer, destroying Yapool's weapon against him and releasing his comrades.