It might not be entirely clear from the comic, but Mium isn’t directly answering her last spoke comment, but rather commenting on her gathering mana to use magic.

I’ve noted before that Mium does not actually catch bullets, he just sometimes gives the appearence of doing so… almost certainly intentionally as we’ve seen he can just destroy something like a bullet at short range. He does it to obscure what he is doing, at least while he’s in a prototype he can move rapidly without harm and isn’t particularly worried if a bullet hits him (compared to Miko, where he had a much lower tolerance for risk).

Ila can move very fast, as long as she is moving in a straight line. In terms of raw speed in a straight line, she is easily the fastest character we’ve seen (I mean, short of Acalia depending on the distance, but that’s sort of cheating). But she’s relying on accelerating herself to do that, compared to someone like Naomi who is boosting her natural movement. Ila seems to be able to do that too, but using that alone wouldn’t be nearly as fast as she can reach with the acceleration magic, but it’s more limited in a way as well.

Ila’s preference for using said power to get up close and personal… well, that’s something of a character defect according to Mium.