Conversation so far:
What was X-Infernus?
X-Infernus is a four-issue comic book mini-series that started in December 2008.
What was X-Infernus about?
X-Infernus was about the X-Men entering Limbo and fighting multiple enemies.
What other events happened in X-Infernus?
Using Pixie's Dagger, Kurt then pulled Illyana's Soulsword from her, and used it to free Wolverine and Colossus of Witchfire's control.

Question: Why did Kurt stop Pixie?
Self-contained rewrite: Why did Kurt stop Pixie?