The Ur-Dragon (Borderless Textured Foil Frame Break) [Commander Masters] Wolf Spirit plus a huge number of

plus a huge number of heads and accessories for customising your Brood Brothers units

but I believe a more mundane power source might suffice

Set: Ravnica Allegiance Promos Type: Land — Forest Island Rarity: Rare ({T}: Add {G} or {U}

{W}{U}{B}{R}{G}: Untap all attacking creatures

Set: Black & White: Plasma Freeze Type: Dragon Rarity: Holo Rare Retreat cost: Colorless

The Ur-Dragon (Borderless Textured Foil Frame Break) [Commander Masters] Wolf Spirit plus a huge number ofSet: Commander Masters Type: Legendary Creature Dragon Avatar Rarity: Mythic Cost: {4}{W}{U}{B}{R}{G} Eminence As long as The Ur Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost {1} less to cast. Flying Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.