The nerd in me is pressuring me to say this, and I want to bring this to the attention of anyone reading. THIS scene right here, and the way it unfolds, is good writing. You wouldn’t think this would be a thing, but it turned out for the better, and you wouldn’t expect it to end up like that. That shows thoughtful planning, unlike most manga nowadays where everything happens so conveniently.
For instance, in most isekai, cultivation, or virtual class system manga, the character gets loot or a skill that seems to be "useless," but it ends up helping them in a time of need. However, most of us (I hope) know that these items will be used by the character, so it’s not a surprise to us. Everything is conveniently tipped in favor of the MC in these stories, making them able to use the items for everything to continue with the messiah complex theme. "Damn! The boss almost killed me-good thing I stuck a 3,000-year-old unicorn horn in my b-hole, and that hit from the boss awakened my Neanderthal bloodline when it dissolved the horn and entered my bloodstream-now I’m nascent soul! And what's this? A reward? Revival pill-oh right, the mother of the girl who showed me the village is dying from diabetes, ILL GIVE IT TO HER!"
Ahem... in this scene, we thought that Iruma summoned Kalego to stop him from popping the others’ hearts, but in reality, it was the writer’s second intention to have him there to protect Iruma from Multi-Arms. We know there are two infiltrators, but we don't know WHEN they will attack. I personally thought they’d stay longer in the school and act later, but NOT during the event. Especially the last scenes of this chapter. WTF?! This is how writing should be done. It keeps you guessing.