Juno as a final boss has a moment. His defenses are staggeringly high, especially compared to all the other bosses in the game. He doesn't have very much health, maybe both forms' gauges combined to equal Bruno's, but he takes so little damage and hits so hard that one missed step means getting smacked in the face with an attack that takes anywhere from a quarter of your health to crushing your Shield and leaving you with no health.
Speaking of Juno, he crosses the Moral Event Horizon of the Bonnes, so they decided to free Mega Man from Juno's trap and send him off to stop Juno from destroying the island.
Another Bonne one, in the first game they seem to die after their airship is destroyed. In a secret side passage in the final dungeon though, you find them holed up with yet another new robot. It then powers up, destroying the building it was contained it, and proceeds to attack with every weapon the previous robots have had!
Data, the monkey-like robot who up until then did not much more than save your game, stopping Eden from destroying the island simply by telling the computer Juno was malfunctioning and his orders were invalid.
It's hard to overstate just how big a twist it is (for both the player and Mega Man, who spends most of the scene with his jaw hanging open) when the character who, up until that point, had just been the squeaky, cute little Non-Human Sidekick/save-point suddenly turns around and pulls a one-man Big Damn Heroes moment using nothing but his own administrative authority...
Data: Interrupt command. Priority command rerouted to Purifier First Class Mega Man Trigger. Under suspicion of malfunction, Bureaucratic Model Third Class Juno has been deactivated by Mega Man Trigger as per Ordinance 103. Mega Man Trigger hereby requests the indefinite postponement of the previous Reinitialization order, and the deletion of Bureaucratic Model Juno's back-up data. Trigger hereby assumes all Bureaucratic authority for the District, and will petition Mother for guidance at a future date.
Computer: Command reroute acknowledged.
"Tron, get on board! It's time to activate...Bruno!"
The battle with the Bonnes' airship: Mega Man single-handedly shoots down an airship the size of a city.
Maxing out the Shining Laser in either game. It's Awesome, but Impractical by itself, but then you can upgrade the energy to never run out. Although it's extremely expensive, to the point of 19 million zenny being needed in Legends 2 to max the only upgradable four of six stats, and you can only make both Shining Lasers by the end game in each title, even the first game's final boss goes down in literal seconds.
After Legends 3 was canceled, thousands of fans are calling for Capcom to reconsider. Even if they don't, the fans' voices were heard.
Forget "thousands of fans". Basically the whole fanbase is putting up a fight for this. All the more awesome when you understand that the Mega Man fanbase is one of the most Broken Bases in video game history.