This is all about your and and Klaus’s love. You and him have been I love when you both were humans, you were turned into a vampire with them, you and Klaus are each other soft spots. In this just shows old romance memories of you and Klaus because you are missing and no one can find you anywhere, meanwhile he is lying in his and yours shared bed with a witch spell burn and since he keeps going In and out of consciousness he keeps getting memories of your and his romance over the 1000+ years you and him have been together. Only your blood can heal it because your the only original vampire that’s not a Mikaelson and ester put that force on you when you were turned. It doesn’t give extra powers just means if a vampire gets a witch spell burn then only your blood can heal them.