Sigzil, Dawnshard of Azir

The "legend rule" doesn't apply to Windrunners or
Skybreakers you control.

Each legendary creature card in your graveyard has
flashback {x}, where X is its mana value.

Dawnshard: If another creature or artifact with
Dawnshard in its type comes into play, flip a coin. The
winner of the coin flip gets to keep their Dawnshard.
Destroy the Dawnshard of the loser of the coin flip.

based on Sliver Gravemother