Well being God I would come down to earth and organize a death tournament, were the winner will be giving the position has my right hand man, the only other being who will have more power than him/her is God, which in this case is me.
I will also use my powers to force them to fight, that way they should have no problem killing loved ones.
However when the tournament is over, and the victor as been decided. Instead of giving them their prize I will simply, inject them with a drug which causes their reaction time to slow down.
In other words five minutes feels like five days. I will then insert a blade into their heart and due to the reaction time drug; they can?t die quickly so they have to suffer for at least one hundred years tops, before dying.