Surprisingly. people usually don't get hurt in Crossed Wands. And, even when they do, it's usually isn't something a few vials of Wiggenweld can't remedy.
That is, unless, Harper is on the field.
The first few times she participated, she understood how important it was to hold back. However, after a few months fighting for her life out in the Highlands, she began to view the dueling club less as an extra curricular activity, and more of a safe space to practice and hone her skills... all of her skills. Soon, students dreaded being paired with her, lest they hobble away with a half-formed chicken foot, or worse, be levitated up to the Hospital Wing, barely conscious.
Sebastian, knowing exactly what she is capable of, is happy to join her team during doubles week of Crossed Wands. Though the proud Slytherin would never admit it, the look she gets in her eye before a match scares him, just a little bit.