The majority of every set
This blade of Arthurian legend gives a creature +10/+0 and vigilance, and its cost of 12 mana is brought down by the total mana value of historic permanents you control
After a turn or two in play, Mowu will more than likely be able to take some serious bites out of your opponents, particularly since he comes with trample built-in
The logic of the scoring system is based on stuff like "real card prices", "prices in shandalar", "ai base value", "rarity" and other stuff
As much as Wizards seem to have concentrated on Black for cheap creature-based exile in cards like Epic Downfall, the need for White to have access to more absolute removal than effects like Oblivion Ring or Conclave Tribunal is crucial to the colors relevancy in Commander
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