I'm competing in my first legacy tourney this weekend and was wondering how to properly navigate an on board Karakas so I can resolve griselbrands ability to dredge my deck? For example, when I dread return griselbrand, can my opponent respond by sending him back to my hand? Or do I still have priority? What about when I go to activate his ability? If I pay the life and try respond by using Karakas, do I still lose the life and not get the cards??