mtg.wtf

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color.

Nontoken creatures are enchantments in addition to their other types.
Constellation — Whenever an enchantment enters the battlefield under your control, you gain 1 life.
Whenever chaos ensues, choose a color. Add an amount of mana of that color equal to your devotion to that color.

Nyx Lotus enters the battlefield tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color.

O-Naginata can be attached only to a creature with power 3 or greater.
Equipped creature gets +3/+0 and has trample.
Equip {2}

Whenever you crank Oaken Power Suit, target creature gets +X/+X until end of turn, where X is the greatest power among creatures you control.

{T}: Prevent the next 1 damage that would be dealt to target creature this turn.

When Oasis Gardener enters the battlefield, you gain 2 life.
{T}: Add one mana of any color.

Equipped creature gets +3/+1.
Whenever equipped creature dies, return that card to the battlefield under your control if it's a Samurai card.
When Oathkeeper, Takeno's Daisho is put into a graveyard from the battlefield, exile equipped creature.
Equip {2}

{1}{W}, {T}: You gain 5 life.
{1}{U}, {T}: Draw a card, then discard a card.
{1}{B}, {T}: Target creature gets -2/-2 until end of turn.
{1}{R}, {T}: Obelisk of Alara deals 3 damage to target player or planeswalker.
{1}{G}, {T}: Target creature gets +4/+4 until end of turn.

{T}: Add {G}, {W}, or {U}.

{T}: Add {W}, {U}, or {B}.

{T}: Add {U}, {B}, or {R}.

{T}: Add {B}, {R}, or {G}.

{T}: Add {R}, {G}, or {W}.

{6}, {T}: Return target permanent you both own and control to your hand.

Convoke
As Obelisk of Urd enters the battlefield, choose a creature type.
Creatures you control of the chosen type get +2/+2.

When you cast this spell, target opponent exiles the top four cards of their library, then you may put any number of land cards that player owns from exile onto the battlefield under your control.

{4}, {T}: Put a fate counter on target permanent.
{5}, {T}, Sacrifice Oblivion Stone: Destroy each nonland permanent without a fate counter on it, then remove all fate counters from all permanents.

Devoid
Exile target creature.

{T}: Add {U}.
{1}: Return Oboro, Palace in the Clouds to its owner's hand.

When Obscura Storefront enters the battlefield, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Equipped creature gets +2/+1 and has haste.
Whenever a Warrior creature enters the battlefield, you may attach Obsidian Battle-Axe to it.
Equip {3}

Obsidian Obelisk enters the battlefield tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a multicolored spell.

Equipped creature gets +5/+0.
Equip {5}