These permanents and spells can cause some real damage and are solid strategies to try and integrate into your Constructed, and especially, Limited builds
The shiny Megas in this set all have a darker hue to them than their normal counterparts
Since Magic: The Gathering has five colors of mana, WotC created a fifth crystal, in the game called The Darkness Crystal, which instead represents a version of the elemental crystals in the world of darkness
Her mana cost is reduced by the amount of life you gained this turn, often allowing her to come down for just three mana despite her high printed cost
Plus, going off power alone isnt enough in a battle, as several other abilities can throw a wrench into the player's plan, so its important to keep in mind that the right way to play this game is to simply play it and have fun
You're more than welcome to activate this ability in response to someone casting a Heroic Intervention in response to a Damnation