Carissa holds the entire population of this universe in immense contempt.
(Well, not really. Probably some of them have learned real magic and just kept it hidden, and plausibly a previous Summoned Hero made a strategic decision to make it look this way, and it's even probable that Summoned Heroes always understand magic and that's why they have to be from out of universe and for whatever reason they've all made the decision not to teach anyone, for good reasons - which would mean that people will recognize her magic and it'll instantly identify her as the latest summoned hero.
She holds them in suspended contempt pending figuring out if any of this is true.
Also, not that she'd previously considered it possible that this magic system beat Asmodeus, but hahahahahahahaha this magic system did not beat Asmodeus.)
Can she prepare Earth-aspected versions of her own spells, so her magic doesn't look aspectless to someone looking carefully? That'd involve getting two different complex structures to interact, so it'd be a hassle, but if she can get an Earth-aspected Mage Armor then she can send Almys out magically armored without giving anything away.
Can she, if Earth-aspected improvised spellcasting can smear blood around, use that to make an offensive combat spell? She'll test it on herself, she's supposed to believe herself to be in grave danger anyway.