Nylea's Huntmaster
Creature — Centaur Shaman
When this creature enters, target creature you control gets +X/+0 until end of turn, where X is your devotion to green. (Each in the mana costs of permanents you control counts toward your devotion to green.)
Nature is stillness and savagery in equal measure.
Winona Nelson
Theros Beyond Death (THB)
• #187Rulings
Mana symbols in the text boxes of permanents you control don’t count toward your devotion to any color.
(wotc • 2020-01-24)
The value of X is determined only as the triggered ability resolves. Once that happens, the value of X won’t change later in the turn even if your devotion to green changes.
(wotc • 2020-01-24)
If an activated ability or triggered ability has an effect that depends on your devotion to a color, you count the number of mana symbols of that color among the mana costs of permanents you control as the ability resolves. The permanent with that ability will be counted if it’s still on the battlefield at that time.
(wotc • 2020-01-24)
Hybrid mana symbols, monocolored hybrid mana symbols, and Phyrexian mana symbols do count toward your devotion to their color(s).
(wotc • 2020-01-24)
If you put an Aura on an opponent’s permanent, you still control the Aura, and mana symbols in its mana cost count towards your devotion.
(wotc • 2020-01-24)
Colorless and generic mana symbols ({C}, {0}, {1}, {2}, {X}, and so on) in mana costs of permanents you control don’t count toward your devotion to any color.
(wotc • 2020-01-24)
Rulings
Mana symbols in the text boxes of permanents you control don’t count toward your devotion to any color.
(wotc • 2020-01-24)
The value of X is determined only as the triggered ability resolves. Once that happens, the value of X won’t change later in the turn even if your devotion to green changes.
(wotc • 2020-01-24)
If an activated ability or triggered ability has an effect that depends on your devotion to a color, you count the number of mana symbols of that color among the mana costs of permanents you control as the ability resolves. The permanent with that ability will be counted if it’s still on the battlefield at that time.
(wotc • 2020-01-24)
Hybrid mana symbols, monocolored hybrid mana symbols, and Phyrexian mana symbols do count toward your devotion to their color(s).
(wotc • 2020-01-24)
If you put an Aura on an opponent’s permanent, you still control the Aura, and mana symbols in its mana cost count towards your devotion.
(wotc • 2020-01-24)
Colorless and generic mana symbols ({C}, {0}, {1}, {2}, {X}, and so on) in mana costs of permanents you control don’t count toward your devotion to any color.
(wotc • 2020-01-24)