Cid is low key a manipulative, morally gray character. Every one of the children were manipulated into the party by him, one unsuccessfully. I actually really, REALLY liked his character when I realized this. The only issue I have is that I wish it was more explicit.

If they ever do a remake, I would love for that to be expanded on or given extra emphasis. Cid is basically Professor X from X-Men.

However, it does add context that he was preparing for the literal end of the world. It's never confirmed if Galbadia was in on the plan or if they just went along with it. But either way, Cid must have been surprised that everyone was kinda okay with teen mercenaries, trained through childhood.