: Add to your mana pool. Spend this mana only to cast artifact spells or activate abilities of artifacts.
, : Search your library for a card named Heart-Piercer Bow or Vial of Dragonfire, reveal it, put it into your hand, then shuffle your library.
11/24/2014 You can use mana generated by the first ability to pay an alternative cost or an additional cost to cast an artifact spell. It’s not limited to paying just that spell’s mana cost.
11/24/2014 An activated ability appears in the form “Cost: Effect.” Some keywords, including equip, are activated abilities.
11/24/2014 Notably, turning a face-down creature face up isn’t an activated ability. If you manifest an artifact creature card or cast an artifact card face down using the morph ability, you can’t use mana generated by the first ability to turn it face up.
11/24/2014 The mana generated by the first ability can’t be spent to activate abilities of artifact sources that aren’t on the battlefield.
11/24/2014 Heart-Piercer Bow is a card from the Khans of Tarkir set. Vial of Dragonfire doesn’t appear to have been invented yet. Curious.