Its color identity is blue and white because of its Plains and Island land types, so it can only be used in decks with commanders that have a color identity with white and blue
If youre willing to wait until your fifth turn to have found the needed legendary creatures and are happy with a 75% chance of having Kolvori be a 6/6, then you only need a mere thirteen non-Kolvori legendary creatures, which is a much easier number to come to and still sounds acceptable to me
It's also amazing with double strike Commanders or enablers like Atarka, World Render and Fireshrieker
It's not triggering any abilities from turning a permanent face up
Black has many other ways to get cards into the graveyard if thats the gameplan, or force multiple opponents to discard if thats the plan
NEOs channel lands are great, with Takenuma, Abandoned Mire providing recursion and self-mill while Eiganjo, Seat of the Empire pads the interaction section