Crucible of the Spirit Dragon
Land
: Add 
.
, : Put a storage counter on this land.
, Remove X storage counters from this land: Add X mana in any combination of colors. Spend this mana only to cast Dragon spells or activate abilities of Dragons.
Jung Park
Rulings
An activated ability appears in the form “Cost: Effect.”
(wotc • 2014-11-24)
The mana generated by the last ability can't be spent to activate abilities of Dragon sources that aren't on the battlefield.
(wotc • 2014-11-24)
You can use mana generated by the last ability to pay an alternative cost (such as a dash cost) or an additional cost to cast a Dragon spell. It's not limited to paying just that spell's mana cost.
(wotc • 2014-11-24)
Notably, turning a face-down creature face up isn't an activated ability. If you manifest a Dragon creature card or cast a Dragon creature card face down using the morph ability, you can't use mana generated by the last ability to turn that card face up.
(wotc • 2014-11-24)
Rulings
An activated ability appears in the form “Cost: Effect.”
(wotc • 2014-11-24)
The mana generated by the last ability can't be spent to activate abilities of Dragon sources that aren't on the battlefield.
(wotc • 2014-11-24)
You can use mana generated by the last ability to pay an alternative cost (such as a dash cost) or an additional cost to cast a Dragon spell. It's not limited to paying just that spell's mana cost.
(wotc • 2014-11-24)
Notably, turning a face-down creature face up isn't an activated ability. If you manifest a Dragon creature card or cast a Dragon creature card face down using the morph ability, you can't use mana generated by the last ability to turn that card face up.
(wotc • 2014-11-24)