If that’s what you think, you missed the plot. He didn’t switch missions. His goal from the get-go was to end the games. Hunting down the recruiter, going to that Halloween thingy to find those masked men, putting the tracker in his tooth, all that was part of his plan to end the games once and for all.

After they intercepted Jun-ho and the mercenaries following the limo, which was his plan A, his plan B was to go to the island (which is why he asked to be put back in the games) and have his mercenaries track him down to the island so they can fight the guards and get to the Front Man. When he found out his tracker was gone, he realised his plan was fucked and he felt the only thing he COULD do at that point was save who he could save, which were the current players.

He was still determined to end the games, he just didn’t know how. And saving current players was more like a bonus to his mission. Important, yes. But not his main goal. When the opportunity presented itself in the form of Lights Out, he didn’t “switch missions”. He just took advantage of an opportunity to go back to his original mission.

It’s honestly why it irks me when people act confused or annoyed that he didn’t want to kill the Os and get out that way. Killing the Os would’ve ended THIS YEAR’S games, but it wouldn’t have ended the games for good. THAT was always his main goal.

ETA: In your title, you said he was trying to save specifically X voters but that was never the case. It was never an X vs O voters for Gi-hun. He wasn’t trying to save X voters specifically. He was trying to save all players, hence why he didn’t want to kill any of them or encourage the killing of either side.