He is also quiet a nice way to greatly increase the punch from a Krenko
Mountain Goat Creature Goat Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.) "Up, yes, in the branches, the purple blossoms go pale at the edges
If The Darkness Crystal leaves the battlefield at the same time as one or more nontoken creatures an opponent controls would die, those creature cards will be exiled and you'll gain 2 life for each of them
In the right deck, you'll find that By Invitation Only can allow you to clean out your opponents while keeping much of your own board state intact
Worst-case scenario, you'll have "scried" and set up your plays for that turn and the next
By discarding a life point, the opponent deprives themselves of a card, and giving you a life point exposes them to a potential trigger effect