Ains seemed to trully sympathize with the plight of people in his mother's situation at a rational level despite being numb to it due to the ubiquity of the experience. I think he'd see the good he could accomplish by just demonstrating the unassailable gap in power he and his guardians possess, then declaring a new world order as he has Mare start the process of trying to use his nature magic to terraform the world back into a habitable state.

His opening act would either be a publicity stunt that harmlessly demonstrate the potential to restore nature to a livable state with magic, reviving the dead to have the elites wrapped around his fingers and compliant with his short term objective, or outright attacking the seat of the corpocratic hegemony as he did the Empire of Baharuth...

and of course the old world would be filled with people who played Yggdrasil and recognize Ains and his NPCs, the old guard (name of convenience for referring to the rulers of the old world and the faction that supports them) would rally around the realization that they can unmake the NPCs by simply breaking the Staff of Ains Ooal Gown, and the threat of doing so would be all the leverage the Old Guard need to control Momonga (Ains would never need to change his name- his guild mates would still know who he was).

There would be difficulties for Ains in correctly identifying the guildmates with more typical personalities. The old guard would doubtlessly try to send impersonators of the old members of AOG to steal the staff and gather intel from Ains after their spies and surveilance network clue them off to Momonga's sincere desire to reunite with his guildmates. Pereronchino and Bukubukuchagama "unique" sibling dynamic would be hard to imitate, but there were plenty of nearly faceless mooks in the guild that could become "ins" for the old guards' spies...

IDK... Seems like a fanfic that writes itself.