Blight-Breath Catoblepas

Text:

When Blight-Breath Catoblepas enters the battlefield, target creature an opponent controls gets -X/-X until end of turn, where X is your devotion to black. (Each in the mana costs of permanents you control counts toward your devotion to black.)

Rulings:

• 1/24/2020 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 black changes.
• 1/24/2020 Colorless and generic mana symbols (<img src="/Handlers/Image.ashx?size=small&amp;name=C&amp;type=symbol" alt="Colorless" align="absbottom" />, <img src="/Handlers/Image.ashx?size=small&amp;name=0&amp;type=symbol" alt="0" align="absbottom" />, <img src="/Handlers/Image.ashx?size=small&amp;name=1&amp;type=symbol" alt="1" align="absbottom" />, <img src="/Handlers/Image.ashx?size=small&amp;name=2&amp;type=symbol" alt="2" align="absbottom" />, <img src="/Handlers/Image.ashx?size=small&amp;name=X&amp;type=symbol" alt="Variable Colorless" align="absbottom" />, and so on) in mana costs of permanents you control don’t count toward your devotion to any color.
• 1/24/2020 Mana symbols in the text boxes of permanents you control don’t count toward your devotion to any color.
• 1/24/2020 Hybrid mana symbols, monocolored hybrid mana symbols, and Phyrexian mana symbols do count toward your devotion to their color(s).
• 1/24/2020 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.
• 1/24/2020 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.