If an effect allows you to spend mana "as though it were mana" of any color or type, that allows you to spend mana you couldn't otherwise spend, but it doesn't change what mana you spent to cast the spell
For playsets of competitive staples like Elesas Sparkle, Genesect V, or Mew VMAX (regular), buying singles is significantly cheaper than opening boxes
Fusion Summon 1 DARK Fusion Monster from your Extra Deck, using monsters from your hand or field as Fusion Material, then, you can gain LP equal to the original ATK of the monster sent to the GY to activate this card
Thats where the card really starts to shimmer
Rhystic Study [Best Blue Tax Effect MTG Commander Staple] Rhystic Study stands as the premier card advantage engine in Commander, taxing opponents spells to fuel your hand
If you do not attack Kangashkahn and knock it out, your opponent will keep drawing cards until they have no cards remaining in their deck