People who seem willing to strongly believe this for purposes of shouting about it, will seem to sort of... suddenly back off, when it comes to selling their souls to Hell, on the basis of the promise that Carissa Sevar will be there to take care of them afterwards.
One gets the impression that a lot of Sevarists would sell their souls to her in exchange for large amounts of money, if they could be certain that Carissa Sevar would be there to receive them, and hammer them stronger. Not all of her cult, not even half of her cult, but a quarter of it, maybe. But - without that certainty - people are afraid even to go Lawful Evil, let alone sell their souls.
(The Mathematical Sevarists hold that this is a totally reasonable way for somebody to act given their current incentives and the payoff matrices.)
...she can find at least some people who think they're going to an Evil afterlife anyways, given their past decisions and realistic inability to afford compensatory donations. Some people who'll sell out for a couple of thousand gold pieces, so they can at least live in wealth they never imagined for the rest of their lives, and maybe maybe maybe there'll be somebody who cares about them, who won't shred them, when that life ends.
It would probably be somewhere around five percent of all her followers in Taldor, if she had time to hunt more of them down.