The battle against Duo was not going as well as could be hoped for Mega Man and his allies. At first, it seemed like their strategy worked quite well, as Astro Man and Tengu Man focused on keeping him pinned - Astro Man with gravity manipulation when he was in his physical form, Tengu Man with his windstorms when he was in his energy state - and the others focused on doing as much damage as they could to him in whatever ways they could from long range.
At first, it seemed to be working well as they were able to inflict a lot of damage, but every time Duo shifted back out of his energy state, it was like he hadn't taken any damage at all. While they were able to hold him back, it was quickly becoming apparent that they would not be able to stop him like this. However, the plan was actually two fold. First, attempt to hold him back long enough that he ran out of energy. Second, failing that, hold him long enough to get him talking again. The parts of him that were recognizable as from his original chassis couldn't be properly analyzed by Earth science, and were indestructible by their methods. Even those parts that weren't from his original body but had survived re-entry were incredibly durable. As such, it quickly became apparent that the third possibility, 'do enough damage to shut him down', was not going to happen.
"How?" Bass demanded angrily as he fired shot after shot. "How are you still moving?"
Duo turned to him as his injuries once more healed. "Justice Energy is a bio-lectric energy source, self propagating. I will not run out." Turning, he blocked a massive ice block hurled at him by Frost Man, catching it and using it to block Search Man's sniper fire.
"Da da da da!" Aqua Man proclaimed loudly as he leapt out of the water behind Duo. "Wooosh!"
Duo, for his part, ignored the water that washed over him and backhanded Aqua Man into the pillars behind him. He then shifted to energy form and shot to the side to avoid Mega Man's Skull Blast.
"Dodge this!" Bass screamed out as Duo landed right in front of him, firing off his Bass Cannon. The massive sonic blast erupted, seeming to consume Duo's entire body. "Booyah!" Bass screamed out, convinced of victory.
The blast faded...revealing Duo completely in energy state before he solidified again. "Not bad," Duo murmured, backhanding Bass into a tree. "But that only works on physical matter."
"...not fair..." Bass grumbled from within the tree. "I actually hit him this time..."
"Well, you've managed a couple small fry!" Tengu Man proclaimed smugly. "Let's see how you handle me!" With that, he charged in, Tengu Blade raised.
"Tengu Man, no!" Protoman called out...too late.
Seeing the attack coming, Duo lifted his hand and caught Tengu Man's head. Bringing it down fast, he crushed the Robot Master's head between his hand and his knee, dropping the broken body when he was finished. "One down."
Protoman stared in shock, then shook himself and opened the comms. "Tengu Man is down! I repeat, Tengu Man is down! Astro Man, try and hold him!"
"Beep!" Astro Man replied, focusing gravity upon Duo as much as he could...only to blink at the hand driven through his chest when Duo dashed in in energy form. "B...Beep?"
"Beep," Duo confirmed before pulling back and unleashing a blue fireball, making Astro Man explode.
"Verily thou art impressive!" Clown Man proclaimed angrily. "However, your slaughter stops here! You shan't escape my grasp! Thunder Claw!" Plunging his long arms into the ground, he gripped Duo around the ankles and sent massive amounts of electricity into him.
Duo flinched as the energy raced through his systems, only to plunge his fist into the ground. Gripping Clown Man's arms around the wrists, he yanked him through the ground before swinging him around his head and hurling him into the sea.
"Any more bright ideas?" Bass demanded of Protoman. "This big plan of yours isn't working, and we're dropping like flies!"
Protoman frowned. "I...have one. But...it's risky. There's no guarantee it will work..."
"We don't have any better options!" Mega Man shouted out as he watched Duo pick Freeze Man up and throw him at Search Man, rendering them both inactive.
"Alright," Protoman agreed, watching as Sword Man lunged in.
"Allo!" Sword Man proclaimed as he slashed at Duo with his sword arm. "My name is Sword Man! You killed my brothers! Prepare to die!"
Growling, Duo blocked the sword swipe and threw a straight punch at Sword Man...only to stare as the Robot Master's top half detached and flew upward before coming back down and linking up with the bottom half.
"Allo!" Sword Man proclaimed again. "My name is Sword Man! You killed my brothers! Prepare to die!"
Lunging forward, Duo smashed Sword Man's sword...only to stare as Sword Man leapt back, the blade regenerating.
"Allo!" Sword Man screamed as he lunged in with a thrust. "My name is-"
"Stop saying that!" Duo screamed out as he unleashed a shock wave, sending both halves of Sword Man flying...though they landed together, and it was only a matter of time before he got back.
"If I'm going to make this work, I need you two to stall him," Protoman explained.
"I think that's all we can man-"
"For five minutes," Protoman continued, interrupting Bass. "And considering he's mowing through us like chaff and we've already lost most of our heavy hitters...eh, I have every confidence in the both of you."
Mega Man smiled nervously. "And this is where you tell me you're just making an obscure reference joke and it'll actually only take 20 or 30 seconds, right?" he pleaded. "...right?"
Protoman smiled softly. "This might help," he offered, handing Mega Man his shield before teleporting away.
Mega Man swallowed convulsively. "So...what do we do now?" he asked Bass as he turned to see Duo hurling Grenade Man into the sea to land on Aqua Man.
"Only thing we can do," Bass admitted. "Go all out." Standing up, he lifted his hand. "Treble, come!"
Treble promptly beamed in beside him.
Nodding, Mega Man lifted his free hand as he clutched Protoman's shield tightly. "Rush, come!" Rush promptly warped in.
"Treble..."
"Rush..."
"Boost!" they cried out together as they fused.
Duo smiled as he watched them. "...show me your real power..."
Arriving back in the lab, Protoman raced to where the Energy Samples were being kept, taking one of each type and setting them on the table in front of him. The idea he'd had was crazy, possibly suicidal, and had next to no chance of working...but short of risking Duo in the altered space of the Four Guardians Vinyl had recreated in the Fortress when she learned he was coming, it was the only thing he had left to keep Duo from getting to Vinyl.
An he couldn't do it alone. So he did what he had, for the longest time, promised himself he would never do.
Command Prompt: Open the Gates of Hell
Protoman flinched internally as he felt the firewalls in his own mind lowered, and something inside him arose...the other half of his fractured personality core.
And here you said you'd never let me out...now who's a hypocrite, Proto?
...Blues...