>>33794229Sol/Luna is the light. Necrozma is apparently the "Great Darkness" mentioned by the Kommo-o page on the official site.
Judging by Necrozma's behavior and everything though, it may not be evil. It just needs to eat light, and even the official site says it's in pain when hunting down its primary foodsource. It may well be that Necrozma is a being of true light that's seen on the background of the covers, but ended up in a claustrophobic prism body.
