Great Old One's Tentacles Impale spreading with no damage

I've been starting up a General's Cry shield charge build and was prior to starting it I was running with the gloves to spread my impales for clear. It worked just fine as I was leveling without GC but the moment I switched over I noticed my clear markedly decrease. Despite it saying "you" the monsters do get impaled but don't take the damage, even when the monsters aren't one shot by the skill.