To be sure, Nirkana Revenant will all but ensure that it will keep itself safe by doubling up on all your mana needs and giving you an outlet for all that extra mana
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Plus, it comes back to your hand when it dies, skirting around commander tax
Pick however many cards youd like to swap, place them on the bottom of the deck, and then draw new cards in equal number from the top
It is more the case of whether the card disadvantage is worth the effect when you are not screwed or flooded, which the depth of filtering with a nice range of costs and the synergy of Looting with so many effects ensure is the case
And if the spirit knights ability doesnt end games, Moonshaker Calvary is still a 6/6 with Flying