Here's the answer to your guess!

World Reset

Chapter 22 – Legendary Heroes

"What!?" The red-haired man asked in disbelief as the saber he swung down had hit a big white sphere of light instead of the brown-haired Guardian.

Meanwhile inside the sphere of light, Vent was looking at Giro as a Cyber-elf in front of him. Three other Cyber-elves were on Giro's left side and three others on his right side. Giro let out a sigh, "You don't realize that you're already strong even without Model O, do you?"

"But I couldn't beat Omega with my ZX form," Vent rejected calmly, "And I don't think I stand a chance against Thomas' Model O form without my OX form."

"It's because you didn't truly mean what you said," Vent looked at his former boss in confusion, "You said that you would protect people, but that's not the desire in your heart. Your desire is no longer for revenge, but instead your desire is to fight anyone you think is wrong."

"But you know that Thomas is wrong to destroy the world!" Vent raised his voice in anger, only to have Giro shake his head.

"His actions might be wrong, but his heart isn't," The brown-haired Guardian looked at his former boss in confusion, "His heart desired peace in the world, but supreme power has driven his insanity out and clouded the true intention of his heart," Giro put his hand over his chest, "You won't succeed in anything you do if it doesn't come from your heart. Your heart is your true desire."

"My desire…" Vent looked down at his chest and put a hand on his chest, "My heart is my true desire…"

"Model Z had taught me a lesson about self-sacrifice," Vent turned to Giro, "A sacrifice without the heart to do so is meaningless, and I saved you and Aile out of my own desire. That's what my heart wants and I don't regret my decision at all," A smile appeared on the blonde's face, "If your true desire is to protect people, then my friends and I will lend you a hand…"

Vent nodded and smiled, "Thanks Boss…"

The sphere of light disappeared, leaving the brown-haired Guardian with his usual red armor instead of dark red. Seven small lights hovered around him as Vent looked up at Thomas and pointed his saber upwards, "Thomas! I respect how you're trying to make the world a better place, but destroying the world is going to make other people suffer!"

"Sacrifice is needed for a better future. This world is fated to be reset!" Thomas slammed his pink saber at Vent.

Vent sidestepped from the saber before jumping on to it and ran up at his head, landing a rolling slash on the blue gem. Thomas aimed his dark blue cannon at the Guardian, who didn't have the time to dodge as he fell and took the big purple laser fired from the cannon. The brown-haired Chosen One was almost thrown back against the wall, but he managed to land safely on the ground right in front of the wall.

A pair of golden tomahawk blades appeared and headed towards Vent, who dodged them without noticing that the blades made a U-turn to go back to him and hit his back. Vent got back to his feet and pulled out his ZX buster before aiming it at the blue gem on the giant's head, only to have the released charged shot missed due to the long distance between him and the gem.

Ice spikes started appearing, raining down on the Chosen Ones as he carefully dodged the spikes before running towards the giant Mega Man to release his charged shot. The shot hit the blue gem, only to have the giant Mega Man counter with giant spiked wheels rolling towards Vent. He dodged the attack by sidestepping and got ready as the pink saber Thomas was holding had started glowing.

The red-haired man stabbed his saber on the spot Vent used to be, but he had jumped away from the saber along with some rocks thrown at him before climbing the saber to land another rolling slash at the blue gem once more. The dark blue cannon started glowing as the Guardian landed on the ground, sending out some fireballs in the size of Vent's body.

Vent braced for the attack, taking most of the fireballs while having himself knocked back due to the impact before he jumped on the cannon and land another rolling slash on the blue gem. Electricity-charged seeds started coming out from behind Thomas, landing around Vent to create an electric barrier on his body.

The Guardian fell to his knees, but managed to get up in time before the rocks around him started to form into rock monsters. Vent slashed the rocks into pieces, making them unable to resurrect, before cursors started appearing all over his body. The dark blue cannon fired a dark purple shot towards the cursor on the right hand, knocking the green saber from Vent's hand.

Purple shots were fired from the dark blue cannon at the cursors on Vent's head, chest, and legs, but he managed to get away from the fired shots and picked his saber up before climbing on to the cannon and jumped to land another rolling slash on the gem before creating a small crack on it. The cracked blue gem started glowing before a black shadow appeared with a pair of sabers.

"Aeolus!" Vent recognized the shadow figure.

Just as Aeolus was about to send out a thunder ball at him, one of the seven lights separated itself to materialize into a green Reploid with two pink sabers. The green Reploid clashed his sabers with Aeolus', cancelling his attack, and allowed Vent to take the opening to climb on to the giant saber and land a small slash on the glowing gem.

Aeolus' shadow disappeared along with the green Reploid before the shadow of the Fire Mega Man appeared with her knuckle busters. Just as Atlas was about to send a wave of fire at Vent, another light from around Vent separated itself before materializing into a male orange-armored Reploid with identical knuckle busters as Atlas' and punched her away to let Vent climb back on to the saber and land another slash on the glowing blue gem.

Atlas' shadow disappeared along with the Reploid before the shadow of Thetis appeared with a pair of ice dragons to be sent out against the Guardian. A female Reploid with light blue armor and a staff appeared and destroyed the ice dragons with her own, allowing Vent to climb and land another slash on the glowing blue gem.

The shadow and Reploid disappeared, leaving Vent to deal with the Shadow Mega Man as he had his kunai ready in one hand while a shuriken in the other. A gust of wind blew before a male Reploid with white helmet and purple armor appeared behind Siarnaq with a kunai on the Mega Man's throat. Vent climbed up and landed another slash, giving the gem more cracks.

The shadow of the Mega Man and the Reploid disappeared before a blond-haired Mega Man fell down on Vent with his green saber ready. The green saber suddenly made contact with another green saber, which belonged to a Reploid with red armor before the shadow of Giro was knocked back by the buster shot coming from a blue Reploid standing beside the red one.

Vent climbed up the saber and slammed his own to the gem, making more cracks on it as Thomas yelled out in pain. The Guardian jumped down after the shadow and the two Reploids disappeared and noticed four shadows started appearing in front of him with one of them had the identical appearance as him.

"No way!" Vent commented as he looked at the four shadows in disbelief, "Even the shadow me, Aile, Ashe, and Grey too…"

"Go ahead, Vent," Giro materialized in front of Vent in his transformed form, "I'll take care of this shadows and you go up to end Thomas' insane plan!"

The Guardian nodded before climbing up on the saber and slammed his green saber with all his might, completely destroying the blue gem before it stopped glowing. Thomas let out a pained yell before his giant armor exploded, destroying most of the room. The red-haired man, who had the cracked armor of Model O, fell to his knees in front of Vent as the explosion died down.

The man looked up as Vent approached him, "Go ahead… just… finish me off…" Without a word, the Guardian put away his saber and buster, "But… why…?"

"My intention has always been to stop you, not to kill you," Vent knelt down beside Thomas and offered him a hand, "Come on, let's stop this satellite from crashing to the Earth and go back to the others."

The former Sage Trinity member looked at Vent's hand before letting out a laugh, "Don't be stupid… I can't go back…" Thomas coughed a bit, "The only way to stop this satellite… is to let me explode along with you and the other pests on board!"

"What?!" Vent backed down in disbelief as he saw Thomas' body glowing.

Another trip to the memory lane is coming up. Until then, have a nice day! (or night)