Alisohn Nilesia info check

That is entirely it.

If you're interested in one idea of what happened to her later, I suggest you have a look at Shemeska's first Planescape story-hour. Former-factol Nilesia makes an appearence.

Dragon #339 has a little more:

"...rumors whisper that her new husband might in fact have sold her into slavery on the lower planes. The truth of the matter remains in question though, as some report having seen the ex-Mercykiller factol recently, publicly confronting and subsequently being utterly destroyed by the Lady of Pain herself. An equal number of reports, however, suggest that she still suffers as the slave of a cornugon called Amaggel in some lower planar pit."

The first rumor is a reference to Shemeska's story hour.

Amaggel is the same cornugon who enslaved Darkwood for ten years, who eventually freed him out of respect, because he couldn't be broken. It was under Amaggel's tools that what Darkwood had been was broken down, and the new, steely, determined Darkwood was forged. The devil's torments made him the man he is today.

In a way, Amaggel could save her.

Young Alisohn had never been anything but a weapon for the abstract principle she worshipped, or, once he figured out how to manipulate her, for him. But perhaps she could become something more.

He knew just the one to teach her.