Reaper King
Legendary Artifact Creature — Scarecrow
( can be paid with any two mana or with 
. This card's mana value is 10.)
Other Scarecrow creatures you control get +1/+1.
Whenever another Scarecrow you control enters, destroy target permanent.
It's harvest time.
イラスト：
The List#SHM-260レア英語適正
裁定
If an effect reduces the cost to cast a spell by an amount of generic mana, it applies to a monocolored hybrid spell only if you’ve chosen a method of paying for it that includes generic mana.
A card with a monocolored hybrid mana symbol in its mana cost is each of the colors that appears in its mana cost, regardless of what mana was spent to cast it. Thus, Reaper King is all colors even if you spend ten colorless mana to cast it.
A card with monocolored hybrid mana symbols in its mana cost has a converted mana cost equal to the highest possible cost it could be cast for. Its converted mana cost never changes. Thus, Reaper King has a converted mana cost of 10, even if you spend 
to cast it.
If a cost includes more than one monocolored hybrid mana symbol, you can choose a different way to pay for each symbol. For example, you can pay for Reaper King by spending one mana of each color, 
and one mana each of four different colors, 
and one mana each of three different colors, 
and one mana each of two different colors, 
and one mana of any color, or 
.