Leo is the youngest of Kaer Moehen's residents. He's not a full witcher - though he has completed his training, he was not subjected to mutilation. Leo comes across as a hot-headed whelp, but is also kind-hearted and good.
It appears that Leo is somewhat fascinated with me. He has heard the ballards about the White Wolf and now holds me in high regard.
Leo was killed by the Professor, one of the leaders of the assault on Kaer Morhen. The boy was too hasty and inexperienced. I wasn't able to help him, even though I was right beside him.