Everything is from Scars of Mirrodin block.
There is no 5-color identity Legendary Creature from Scars of Mirrodin block, so I punted and use Etched Monstrosity.
If someone ever were to balk at it (no one ever does), I would go off-theme and use Sliver Queen.
Click here for a text version of this decklist
Click here for my EDH Commander decks