These seem to me like they are riddles, giving us specific instructions in the areas we are in, for instance "Every king must kneel before death" I feel as if he is telling us to kneel before someone of importance such as "The nameless king" which is a rare spawn not too far away from where we saw Arthus, so maybe kneeling on top of his grave summoning him then kneeling or killing him then kneeling to his spirit? Just an idea.