mtg.wtf

Flying
Whenever Numot, the Devastator deals combat damage to a player, you may pay {2}{R}. If you do, destroy up to two target lands.

Whenever a player casts a green spell, you may pay {1}. If you do, target creature gets +1/+1 until end of turn.

Flying
When Nurturing Pixie enters the battlefield, return up to one target non-Faerie, nonland permanent you control to its owner's hand. If a permanent was returned this way, put a +1/+1 counter on Nurturing Pixie.

Whenever you gain life, you may put that many +1/+1 counters on each creature you control. Do this only once each turn.

You have no maximum hand size.
Sonic Booster — Whenever Nyssa of Traken attacks, sacrifice X artifacts. When you sacrifice one or more artifacts this way, tap up to X target creatures and you draw X cards.
Doctor's companion

At the beginning of combat on your turn, target enchanted creature or enchantment creature you control gets +1/+1 and gains trample until end of turn.

Reach
At the beginning of your upkeep, mill two cards.
{1}{B}{G}, Exile Nyx Weaver: Return target card from your graveyard to your hand.

Bestow {1}{R}
Enchanted creature gets +1/+1.

Bestow {4}{U}
Enchanted creature gets +2/+3.

O-Kagachi Made Manifest is all colors.
Flying, trample
Whenever O-Kagachi Made Manifest attacks, defending player chooses a nonland card in your graveyard. Return that card to your hand. O-Kagachi Made Manifest gets +X/+0 until end of turn, where X is the mana value of that card.

Flying, trample
Whenever O-Kagachi, Vengeful Kami deals combat damage to a player, if that player attacked you during their last turn, exile target nonland permanent that player controls.

When Oaken Brawler enters the battlefield, clash with an opponent. If you win, put a +1/+1 counter on Oaken Brawler.

Flying, vigilance
{T}: Add {U}. Spend this mana only to cast an artifact spell or activate an ability of an artifact source.

Vigilance, trample

Constellation — Whenever Oakheart Dryads or another enchantment enters the battlefield under your control, target creature gets +1/+1 until end of turn.

You may cast Oakshade Stalker as though it had flash if you pay {2} more to cast it.
Daybound

{T}: Add one mana of any color.
{T}, Exert Oasis Ritualist: Add two mana of any one color.

Oathsworn Vampire enters the battlefield tapped.
You may cast Oathsworn Vampire from your graveyard if you gained life this turn.

{T}: The player whose turn it is may end the turn.

Companion — Your starting deck contains only cards with odd mana values and land cards.
If a source you control with an odd mana value would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

If it's neither day nor night, it becomes day as Obsessive Astronomer enters the battlefield.
Whenever day becomes night or night becomes day, discard up to two cards, then draw that many cards.

Flying
Ward {2}
Whenever Obsessive Collector deals combat damage to a player, seek a card with mana value equal to the number of cards in your hand.

{T}: Draw a card, then discard a card.
{2}{U}{B}, {T}, Sacrifice Obsessive Stitcher: Return target creature card from your graveyard to the battlefield.

{1}{R}{R}: Put a blaze counter on target land without a blaze counter on it. For as long as that land has a blaze counter on it, it has "At the beginning of your upkeep, this land deals 1 damage to you."