The Grand Overseer

Indestructible
The Grand Overseer is not a creature unless each opponent controls 5 or more Legendary creature.
Whenever The Grand Overseer were to enter the graveyard, instead, shuffle it into your library.
{x}{w}{u}{b}{r}{g}{t}: reveal the top X cards of
each player's library, then gain 3 life for
each Legendary pernament revealed this way,
then each player puts each Legendary pernament revealed this way into their hands and the
rest into their owners graveyard.