Obstinate Baloth
Casting Cost:
When Obstinate Baloth enters the battlefield, you gain 4 life.
If a spell or ability an opponent controls causes you to discard Obstinate Baloth, put it onto the battlefield instead of putting it into your graveyard.
$ 000
Obsianus Golem
Oboro, Palace in the Clouds
: Add to your mana pool.
: Return Oboro, Palace in the Clouds to its owner's hand.
Oblivion Stone
, : Put a fate counter on target permanent.
, , Sacrifice Oblivion Stone: Destroy each nonland permanent without a fate counter on it, then remove all fate counters from all permanents.
Oblivion Ring
When Oblivion Ring comes into play, remove another target nonland permanent from the game.
When Oblivion Ring leaves play, return the removed card to play under its owner's control.
Obliterate
Oblation
The owner of target nonland permanent shuffles it into his or her library, then draws two cards.
Obelisk of Urd
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for 1 or one mana of that creature's color.)
As Obelisk of Urd enters the battlefield, choose a creature type.
Creatures you control of the chosen type get +2/+2.
Ob Nixilis, the Fallen
Landfall — Whenever a land enters the battlefield under your control, you may have target player lose 3 life. If you do, put three +1/+1 counters on Ob Nixilis, the Fallen.
Ob Nixilis Reignited
+1: You draw a card and you lose 1 life.
-3: Destroy target creature.
-8: Target opponent gets an emblem with "Whenever a player draws a card, you lose 2 life."
Ob Nixilis of the Black Oath
+1: Each opponent loses 1 life. You gain life equal to the life lost this way.
-2: Put a 5/5 black Demon creature token with flying onto the battlefield. You lose 2 life.
-8: You get an emblem with ", Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."
Ob Nixilis of the Black Oath can be your commander.
Oath of Nissa
When Oath of Nissa enters the battlefield, look at the top three cards of your library. You may reveal a creature, land, or planeswalker card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
You may spend mana as though it were mana of any color to cast planeswalker spells.