Hey guys, so this though just jumped into my head, and as I thought, I thought more and more.
Was Emperorian the last of his kind?
Think about it, we never heard about their being more of his kind, in fact, all references to his people begin and end with him. It was just him, who attacked the Land of Light, his world was a desolate abandoned sphere, covered in darkness which he used as a space ship. The closest being to him was a suit of armor he created and why was it so hard for him to heal himself (thirty thousand years) and why did he have to go through so much trouble to revive. The Four Kings had less trouble. Here my theory.
My theory is this, Emperian is/was a life similar to Aarb, that hive mind race of crystals that Hikari befriended, only instead of spreading themselve outward, the amalgamated into a humanoif form. However, while Aarb developed into a peaceful race, the Emperians became war like and based on minus energy/darkness.
Now think about this, when the emperor died, what did we see, light? Actually we saw small pieces of crystal, sparkling as he broke apart into light particles. That could have been the director being artsy, but here's another thing, how he spoke.
Now I just assume that the Emperor used the Royal We (while others that I say comment, believed it was a translation error or joke by the subbers). For those who don't know, once upon a time, many nobles of different cultures, refered to themselves in the plural form. They said 'we' instead of 'I' and similar pronouns. This was meant to show their 'better than you' nature by implying they were worth more than any one person.
Now what if none of these previous assumptions were correct? What if the Emperor wasn't using the royal we, what if he was speaking as a hive mind. Aarb referred itself as 'we', and in the pasts aliens announced themselve as 'we' because they were introducing their species, not just themselves. Heck, often times, Yapool refers to himself as 'we' and we know he's an amalgamation of an entire species.
Now I don't know anything about the process of revival in the Ultraman Universe (honestly it's used for easy threats and a cheap gimmick at times) but let's look at things this way. Alien Mephilas, a thriving species that was once endangered, Groza, his race seems to be alright, Deathrem, the same, we can assume that Yapool was inhabiting Ace Killer while he regenerated. Why so much trouble to revive the Emperor, didn't anyone have any of his genetic data lying around to just rebuild his body. Now I admit, this is my weakest bit of evidence, as it relies mostly on assumption, but given how powerful he was, was it that being a single member of a species, make it hard to revive, did his conversion into pure light have anything to do with it? After his duel with Father of Ultra, you would think that he would've gone home to a doctor, but wait. His planet is deserted, empty, as if he's the only one that lives there.
So what if, the Emperor was the amalgamation of his entire race, this is why his planet is deserted, why he spoke of himself in the plural form. No one seems bothered by the idea of a race of beings like him, as if they know there was only his one person.
Food for thought, no?