@javaniy @Owyn
If you look back to the golem fight the fire stopped in time stop as well but it continued to be fire, unless its cast in time stop magic DOES freeze in place, but it continues to have effect. This is why when he went to stab the cockatrice he passed through where the gaze attack hit and turned to stone same as if he'd been hit by it. So basically fire remains hot, lightning gives off infinite charge etc and continues to have an effect during the time stop. Possibly this is how he actually cooks since maybe if he freezes a fireball in the air and moves something into it it would now just be heating up to the heat of the fire forever. Or maybe that's just not thinking it through.
But the meteors are behaving exactly the same way as magic has in the past so long as its cast outside of the time stop. Honestly if Sekai wanted to be more thorough and didn't mind spending years again he probably could have saved the capital by building, or making scaffolding to let him go up and slowly chunk away at the meteors and then move the pieces somewhere else. Probably could have basically killed all the bad guy's forces then as well other then the big bad. Assuming the darkness doesn't do anything like turn off his powers.