There's a flash of contempt -
There's a flash of contempt openly in Peranza's thoughts. It's safe to think that Sevar is a fool, because the Security reading her thoughts will be thinking that too. If you look at the way Cheliax is set up, that Hell is set up, you'd have to be a fool to think they'd ever bother to make devils in a way that didn't hurt. The people of Cheliax are not that lied-to, they are not that sheltered, they are openly told that Asmodeus's domain is tyranny and that their suffering is pleasing to Him.
"Why believe Hell would go along with making devils less painfully?" Peranza says. It does not take heresy, it is not an executable offense, if you suggest that Hell doesn't regret hurting you in the course of your correction. The corrected deserve for the correction to hurt, and the weak deserve to suffer; this is the doctrine of Hell. Peranza has had to whip her classmates, and practice torture spells on children with no other uses, to make sure she experiences it from both sides, just like any other wizard. Even if they could make devils painlessly, they wouldn't.