The Phyrexian forces marched through, compleating all they touched ZURGO AND OJUTAI Though he had been harassed and beset by dragons throughout his life, Zurgo was the first to understand that dragons and non-dragons would not be able to survive without each other's help and would have to work together if they were to save Tarkir
I love this in Rakdos Group Slug, Grixis Wheels Brews, Orzhov Life Gain, and loads more
None of these modes separately is worthy of the grade Im giving Battle Menu, but the flexibility of having access to all four bumps it up dramatically
It's trivially easy to get it into your graveyard: that puts an Artifact into the graveyard, handy for turning on a Dragon Rage Channeller's Delirium ability or pumping up a 'Goyf, and providing another card
And since you can tap your commander to untap Leyline Dowser, that can happen whenever your commander doesn't attack for the turn (or do anything else that requires tapping)