Character from Prince of Thorns by Mark Lawrence
Jorg's baby brother — killed in the briar patch attack, the ghost who haunts every decision Jorg makes.
William was Jorg's younger brother, killed alongside their mother during Count Renar's attack when Jorg was nine. He was an infant. His death is the foundational trauma of the trilogy — not just that Jorg lost his family, but that the family he lost included someone who never had a chance to be anyone. Jorg carries William throughout the series — not as a character but as an absence, a weight, a question about what might have been. William is the reason 'why' behind everything Jorg does, even when Jorg himself can't articulate it. The dead brother is more present than most living characters.
An infant. That's the horror. He was a baby when he was killed. Jorg remembers him as tiny, helpless, and dead in the thorns beside their mother.