Could Necrozma be a Arceus part like the Creation trio (and Arceus)? Ultra Necrozma (Which is the true form) does have that golden noble glow and it is a Dragon like the rest of the trio. if i got things right the Totem Pokemon use Z-Power which is Necrozmas power and they and their relationship of being cared for by Trial Captains seem similar to that of the Nobles and their Wardens. Different Dimension of Origin i know, but that does not really really preclude a relation.