2014-11-24 : An activated ability appears in the form “Cost: Effect.”

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.

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.

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.