Were on a go wide token spam strategy, and when Mirri attacks our tokens become harder to block
Underground Sea (Alpha Edition) $27,000 PSA 10 Gem Mint Why It's Valuable: The king of "dual lands" (Blue/Black)
Bonehoard is at a minimum a Mortivore (power and toughness equal to creatures in all graveyards), which is already in most Type 4 stacks, and this thing generally sticks around even after you kill off the creature token
Flying + menace means they need two flyers and/or reachers to block which at a multiplayer table not everyone can do
Why make extra attacks if it costs your attackers to do so
The ludicrous excess of a seven-mana ramp spell practically screams Commander, and given how easily you can go infinite by using that mana to flicker, reanimate or recast Beledros, I expect this to quickly join the staples of that format