You can find legendary team-ups in March of the Machine , which can be preordered from your local game store or from online retailers like Amazon
100-card ready-to-play Warhammer 40,000 Commander Deck Necron Dynasties Black Deckcontains 2 legendary traditional foil cards plus 98 nonfoil cards Every card features Warhammer-themed artincluding 42 cards that are new to Magic 1 foil-etched Display Commander 10 double-sided tokens, 1 life tracker, and 1 deck box Forces of the Imperium Commander (1) Creature (30) Arco-Flagellant Assault Intercessor Bastion Protector Belisarius Cawl Callidus Assassin Celestine, the Living Saint Commissar Severina Raine Company Commander Cybernetica Datasmith Epistolary Librarian Grey Knight Paragon Inquisitor Eisenhorn Marneus Calgar Neyam Shai Murad Primaris Chaplain Primaris Eliminator Redemptor Dreadnought Sanguinary Priest Sicarian Infiltrator Sister Hospitaller Sister of Silence Sister Repentia Space Marine Devastator Space Marine Scout Thunderwolf Cavalry Triumph of Saint Katherine Ultramarines Honour Guard Vanguard Suppressor Vexilus Praetor Zephyrim Instant (6) And They Shall Know No Fear Deny the Witch Entrapment Maneuver Mortify Swords to Plowshares Utter End Sorcery (8) Collective Effort Deploy to the Front Exterminatus Fell the Mighty For the Emperor
It makes cheap tokens with cards like Krenko's Command and Hordeling Outburst
It's also not hyper mana efficient, as Mistrise Village effectively costs 2 mana to use this ability
Weigh the risk of spending turn four to ramp versus falling behind on board
Moreover if you do the math, drawing many cards gives you card advantage and access to all other aspects of your deck more quickly, so you have greater chance to have access to more lands, ramp, removal, utility, creatures, combo pieces, even more card draw and any other strategy you may run in your deck
