The activated ability is a mana ability. It doesn't use the stack and can't be responded to.
15-09-2013
wotc
Mana symbols in the text boxes of permanents you control don't count toward your devotion to any color.
15-09-2013
wotc
Hybrid mana symbols, monocolored hybrid mana symbols, and Phyrexian mana symbols do count toward your devotion to their color(s).
15-09-2013
wotc
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.
15-09-2013
wotc
Numeric mana symbols ({0}, {1}, and so on) in mana costs of permanents you control don't count toward your devotion to any color.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.