Genocidal is an Inventionperk that allows the player to deal up to 7% extra damage with their weapon, depending how far through their Slayer task they are. It can be created in weapon and armour gizmos.
Genocidal can be obtained in conjunction with Undead Slayer in the same gizmo. One cheap way of achieving this is to combine 1 Bandos component with 1 Undead component. This creates a desirable gizmo for training Slayer.