WMG / Marvel Anime: Blade

In the anime, Blade likes knives so much because of his mother.

In his mother's Death by Origin Story, she makes one last futile stand against Deacon Frost by trying to knife him. Though she only manages to slit his palm, it leaves a permanent scar. Furthermore, the knife she used is also seen in the end credits next to a photo of her, which implies that Blade kept it as a last memory of her. His love of blades only grew from there.