Name: Ondu Spiritdancer Cost: 4W Type: Creature -- Kor Cleric Pow/Tgh: 3/3 Rules Text: Whenever an enchantment you control enters, you may create a token that's a copy of it. Do this only once each turn. Set/Rarity: Commander Masters rare, Duskmourn: House of Horror Commander rare Price: $1.39

Name: Ondu War Cleric Cost: 1W Type: Creature -- Human Cleric Ally Pow/Tgh: 2/2 Rules Text: Cohort -- {T}, Tap an untapped Ally you control: You gain 2 life. Set/Rarity: Oath of the Gatewatch common, The List common Price: $0.08

Name: One Last Job Cost: 2W Type: Sorcery Rules Text: Spree (Choose one or more additional costs.) + {2} -- Return target creature card from your graveyard to the battlefield. + {1} -- Return target Mount or Vehicle card from your graveyard to the battlefield. + {1} -- Return target Aura or Equipment card from your graveyard to the battlefield attached to a creature you control. Set/Rarity: Outlaws of Thunder Junction rare, Outlaws of Thunder Junction Promos rare Price: $0.18

Name: One Ring to Rule Them All Cost: 2BB Type: Enchantment -- Saga Rules Text: (As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I -- The Ring tempts you, then each player mills cards equal to your Ring-bearer's power. II -- Destroy all nonlegendary creatures. III -- Each opponent loses 1 life for each creature card in that player's graveyard. Set/Rarity: Tales of Middle-earth Promos rare, The Lord of the Rings: Tales of Middle-earth rare Price: $1.90

Name: One Thousand Lashes Cost: 2WB Type: Enchantment -- Aura Rules Text: Enchant creature Enchanted creature can't attack or block, and its activated abilities can't be activated. At the beginning of the upkeep of enchanted creature's controller, that player loses 1 life. Set/Rarity: Gatecrash uncommon, RNA Guild Kit uncommon Price: $0.10

Name: One with Nothing Cost: B Type: Instant Rules Text: Discard your hand. Set/Rarity: Saviors of Kamigawa rare, The List rare Price: $1.22

Name: One-Eyed Scarecrow Cost: 3 Type: Artifact Creature -- Scarecrow Pow/Tgh: 2/3 Rules Text: Defender Creatures with flying your opponents control get -1/-0. Set/Rarity: Innistrad common Price: $0.10

Name: Oni Possession Cost: 2B Type: Enchantment -- Aura Rules Text: Enchant creature At the beginning of your upkeep, sacrifice a creature. Enchanted creature gets +3/+3 and has trample. Enchanted creature is a Demon Spirit. Set/Rarity: Champions of Kamigawa uncommon, Duel Decks: Divine vs. Demonic uncommon, Duel Decks Anthology: Divine vs. Demonic uncommon Price: $0.15

Name: Onulet Cost: 3 Type: Artifact Creature -- Construct Pow/Tgh: 2/2 Rules Text: When this creature dies, you gain 2 life. Set/Rarity: Antiquities uncommon, Foreign Black Border rare, Revised Edition rare, Summer Magic / Edgar rare, Fourth Edition rare, Fourth Edition Foreign Black Border rare, Masters Edition common, Masters Edition IV common Price: $0.32

Name: Onyx Goblet Cost: 2B Type: Artifact Rules Text: {T}: Target player loses 1 life. Set/Rarity: Shards of Alara common, Salvat 2011 common Price: $0.07

Name: Onyx Mage Cost: 1B Type: Creature -- Human Wizard Pow/Tgh: 2/1 Rules Text: {1}{B}: Target creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.) Set/Rarity: Magic 2012 uncommon Price: $0.14

Name: Onyx Talisman Cost: 2 Type: Artifact Rules Text: Whenever a player casts a black spell, you may pay {3}. If you do, untap target permanent. Set/Rarity: Ice Age uncommon Price: $0.25

Name: Oona's Blackguard Cost: 1B Type: Creature -- Faerie Rogue Pow/Tgh: 1/1 Rules Text: Flying Each other Rogue creature you control enters with an additional +1/+1 counter on it. Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, that player discards a card. Set/Rarity: Magic Online Promos uncommon, DCI Promos rare, Morningtide uncommon, Jumpstart uncommon, Zendikar Rising Commander uncommon Price: $0.41

Name: Oona's Prowler Cost: 1B Type: Creature -- Faerie Rogue Pow/Tgh: 3/1 Rules Text: Flying Discard a card: This creature gets -2/-0 until end of turn. Any player may activate this ability. Set/Rarity: Lorwyn rare, Double Masters 2022 rare Price: $0.15

Name: Opal Acrolith Cost: 2W Type: Enchantment Rules Text: Whenever an opponent casts a creature spell, if this permanent is an enchantment, it becomes a 2/4 Soldier creature. {0}: This permanent becomes an enchantment. Set/Rarity: Urza's Saga uncommon Price: $0.22

Name: Opal Archangel Cost: 4W Type: Enchantment Rules Text: When an opponent casts a creature spell, if this permanent is an enchantment, it becomes a 5/5 Angel creature with flying and vigilance. Set/Rarity: Urza's Saga rare Price: $2.59

Name: Opal Avenger Cost: 2W Type: Enchantment Rules Text: When you have 10 or less life, if this permanent is an enchantment, it becomes a 3/5 Soldier creature. Set/Rarity: Urza's Legacy rare Price: $0.33

Name: Opal Caryatid Cost: W Type: Enchantment Rules Text: When an opponent casts a creature spell, if this permanent is an enchantment, it becomes a 2/2 Soldier creature. Set/Rarity: Urza's Saga common Price: $0.17

Name: Opal Champion Cost: 2W Type: Enchantment Rules Text: When an opponent casts a creature spell, if this permanent is an enchantment, it becomes a 3/3 Knight creature with first strike. Set/Rarity: Urza's Legacy common Price: $0.09

Name: Opal Gargoyle Cost: 1W Type: Enchantment Rules Text: When an opponent casts a creature spell, if this permanent is an enchantment, it becomes a 2/2 Gargoyle creature with flying. Set/Rarity: Urza's Saga common Price: $0.13