I think it's interesting and cool that Mephistio is saying that he will guide Iruma as a King Maker!
Not as a member of the 13 crowns. No- Mephistio is acting as a guide!
He was probably watching and backing up Azz and Clara as they got the kids to safety. Right now the only long-ears left appears to be Nova, who probably wouldn't of moved anyways. Or maybe he just didn't hear the slight whisper from Azz and Clara to 'come here to safety'.
Then he watched as Iruma made his decision.
Iruma discarded the fact he probably couldn't win. Iruma is protecting both his and the long ears dreams. Iruma is being extremely greedy right now- he's refusing to allow both dreams to be trampled upon.
Mephistio is now acting as a guide. Iruma said he wanted one. Iruma said he'd happily make Mephistio's dreams come true as well. So Mephistio will now Guide Iruma to the end result.
It makes me wonder if he would've moved before, for the sake of the exam. It sounded like he was thinking of politics "It's hardly the wisest move to toss your own position into jeopardy". Meaning would've Mephistio decided to allow it to be trampled and used politics to move again Narnia?
But, he finishes with: Knowing your own powerlessness, and still standing up to protect the clans pride... Without a doubt, that determination is an irreplaceable quality for a 'king'.
So it feels like Mephistio is solidifying his own stance- he is the King Maker, and Iruma has proven his qualities. He is moving not as 13 crown, but really as a King Maker.