Sonic the Hedgehog

Sonic the Hedgehog is the protagonist from the Sonic the Hedgehog series. Hailing from Planet Mobius, Sonic acted as the hero of the planet, as well as the leader of the Freedom Fighters. He is most known for his super speed, which allows him to break the sound barrier.

Worlds Collide
In the world modified by the Genesis Wave, Sonic learned of the disappearances of his friends Miles "Tails" Prower, Knuckles the Echidna, and Amy Rose. Deducing that Doctor Eggman was responsible for their disappearances, he asks the Chaotix to help him find for his friends and they start searching in different locations. While checking in the Green Hill Zone, Silver the Hedgehog appears to talk with Sonic, but he is abducted by Copy Robot, who tricks him into fighting Mega Man shortly after. Sonic believes that Mega Man is one of Eggman's Badniks due to his robotic nature, and he fights against him to discover where his friends are. Mega Man, likewise, believed him to be an incredibly advanced robot who might have been working for Dr. Wily. According to Mega Man, Sonic is faster than any of Wily's robots he had encountered by that point, most notably Quick Man and Nitro Man.

At first the two blue heroes are evenly matched, but Sonic uses the landmark and his speed for his advantage, and he manages to disable Mega Man's Mega Buster. However, Dr. Light manages to reopen the portal between the two worlds, and Mega Man returns home, taking Sonic with him. Mega Man calls Rush, Eddie, Beat and Tango to help him, using Eddie to enable his Mega Buster and recover energy. Sonic complains of Tango, who uses an attack similar to his. At one point Mega Man starts chasing Sonic with the Rush Jet, and he tries to convince Sonic to return the jewel he and his friends stole from the museum. Sonic says he didn't steal anything and states that Mega Man kidnapped his friends, who replies that he hadn't kidnapped anyone.

They were then ambushed by the Roboticized Master, Tails Man, who had secretly been observing their battle under Eggmn and Wily's orders. Sonic and Mega Man then called a truce to save the innocent civilians caught in Tails Man's attack. Afterwards, they then teamed up to attack Tails Man. After disabling Tails Man, Mega Man attempted to use his Special Weapon copying ability to find out any information on Tails Man, only for the Roboticized Master to unexpectedly revert back to his original form, Tails, when touched. Sonic is glad to see Tails again, and also learned from Tails that Wily and Eggman had teamed up and were responsible for Tails and the others' abduction. They then were teleported by Mega Man to Light Labs (with Sonic becoming queasy from experiencing the teleportation aspect from Mega Man's realm), and were eventually dispatched to the Skull Egg Zone, alongside Rush and Proto Man. They later fought against the Genesis Unit and Copy Man, easily defeating them, and eventually encountered the other Roboticized Masters. Sonic and Mega Man later fought against Vector Man, Charmy Man, and Espio Man, personally ensuring Mega Man took down Espio Man when the latter tried to ambush him with Chrome Camo. He, alongside Mega Man, later fought against both the Roboticized Master and the Robot Master Shadow Man (causing confusion among them due to their having the same name). The Roboticized Shadow Man then used Chaos Cannon on Sonic until Mega Man disarmed Shadow Man with Tail Wind and reverted him back to Shadow the Hedgehog. He later recovered most of his memories of his past life, or rather, that of the first Genesis Wave, when witnessing Shadow use Chaos Control. Afterwards, he and Mega Man then tried to fight Silver Man and Blaze Woman. However, Blaze Woman nearly killed him and tails with Flame Tornado, although Silver stopped it. Afterwards, they then were ambushed by Rose Woman and Knuckles Man (who warped in ironically after Sonic expressed hope that they just ambush them). Both he and Mega Man barely managed to revert them before they self-destructed. Later, Sonic and Amy went out to search for Shadow the Hedgehog. Afterwards, Sonic and the rest of the characters regrouped and fought against several Robot Masters to get to the teleporter. During the fight, Sonic slid under Mega Water S and then kicked him into the air, also knocking out several Robot Masters in the process, before elbowing Plant Man, all while conversing with Mega Man about needing to get to the teleporter. He then aided Proto Man and Mega Man by using a homing attack on Knight Man, and also managed to take out Hard Man, Spark Man, and Bright Man, also taking out Top Man for Shadow, to the latter's irritation. He then fought against Quick Man (who bragged about his speed), Charge Man, Slash Man, Metal Man, Turbo Man, and Nitro Man while also commenting they don't have Mega Man's skills. Sonic likewise aided Mega Man in reverting Rouge Woman back to Rouge the Bat by dragging her down. He later managed to take down Bubble Man, Needle Man, Ring Man (which makes Sonic look at the Rings he collected from the Robot Master), Tomahawk Man, Search Man, Wave Man, Ground Man, Jewel Man, Strike Man (in which Sonic gave a "seriously?" look at the Robot Master), Buster Rod G, Drill Man, and finally kicked Quick Man, as Sonic replied that although Quick Man is quick, he's not "fast" like Sonic.

Sonic and Mega Man, alongside Rush and Tails, later broke off the attack to go directly for the Wily Egg to save Dr. Light. However, when they notice Dr. Light being thrown out of the Wily Egg, Sonic panics as Light is falling directly into the crater and thus Sonic can't save him. After Light is saved by Shadow, Sonic and Mega Man then proceeded to enter the Wily Egg after Tails cracked the code, and proceeded to fight the Mega Man Killers. Sonic and Mega Man managed to wipe out Enker and Punk by ramming them into each other, and then proceeded to finish off Ballade, although not before the latter wounded Tails with one of his attacks. Sonic and Mega Man then proceeded to fight the Chaos Devil, although they couldn't beat it, and Sonic ended up trapped after an attempt to double team it backfired until they were saved by Duo. Racing towards the central area of the Wily Egg, they eventually confronted Bass and Metal Sonic, the last defense.