You know what, now that I think about it, it might actually just be a ship.
Remember one of the themes in the Arc that Pluton was introduced in. The Battle Franky series of ships that Franky built, strong tiny ships that Franky built not as destructive weapons but in good spirit (his intention was to hunt Sea King with them). Then Spandam used those ships with evil intent to destroy the Judicial Ship, and put the blame on Tom, Franky and co.
As Franky curses himself for ever building those ships in the first place, Tom says this
In other words, even if the Pluton is a dangerous battleship, it always depends on how it is used, be it for good or for evil. Even the largest battleship is not evil in nature. For example, Momo desires to be strong enough to protect Wano himself. So, if Wano's borders are opened, and Pluton is released, Momo and take command of Pluton and "use it for good." Whereas if Kaido had ever gotten Pluton in his 20 year reign, if would be used "for evil".
The most I can imagine Oda pull of is perhaps that he makes Pluton sentient in some form. As Tom implied, every ship embodies the spirit of its creator. So if Pluton's creator didn't want the ship to fall in the hands of evil, then Pluton might have some sort of selective control mechanism (like Zunesha only being able to controlled by Momo). Perhaps in the same vein, Pluton can only be controlled by people with a D. in their name or something (and then used to eventually help in destroying the Celestial Dragons, the enemies of the D.)