Wait can someone explain the truyde family thing? I'm confused

Truyde family is one of the great families, these families composed a group that secretly controlled the previous King. Currently the head is the duke who harbors ill intentions against the current king (ml). Using black substance to secretly poison the ml since his infancy as well as his mother who became the awful mother she is partly due to the substance. The black substance was the poison used to kill Abel (mc) in his first life. Currently the ml is trying to plot revenge killing a member would arise suspicion.

Ty!