Turn target creature with a morph ability face down. Cycling {U} ({U}, Discard this card: Draw a card.)

Counter target spell. Investigate three times. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Face-down creature spells you cast cost {1} less to cast.

Five Hundred Year Diary enters tapped. {T}: Add {U} for each Clue you control. {2}, Sacrifice Five Hundred Year Diary: Draw a card.

{T}: Manifest a card from your hand. (Put that card onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Put target permanent on top of its owner's library. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

If you would create a Clue, Food, or Treasure token, instead create one of each.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.) If one or more tokens would be created under your control, twice that many of those tokens are created instead.

Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.) When this creature is turned face up, destroy target artifact or enchantment an opponent controls.

{T}: Untap target artifact or creature. Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Whenever a permanent is turned face up, you may draw a card.

As this creature enters or is turned face up, it becomes your choice of 5/1 or 1/5. Morph {2}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Trample Morph {G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Vigilance (Attacking doesn't cause this creature to tap.) When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") As long as you control a token, this creature gets +2/+0.

Whenever this creature is dealt damage, you may create that many 1/1 green Insect creature tokens. Morph {2}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, you may tap or untap target permanent.

When this creature enters or is turned face up, target creature blocks this turn if able. Disguise {4}{G} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)

Deathtouch Whenever a permanent you control is turned face up, you may return this card from your graveyard to the battlefield face up or face down. Megamorph {4}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Creatures with power less than this creature's power can't block it. Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.) When this creature is turned face up, return target card from your graveyard to your hand.

Morph—Reveal a blue card in your hand. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, look at target opponent's hand.

{U}, {T}: Target creature attacks target opponent this turn if able. Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Flying Whenever you investigate for the first time each turn, investigate an additional time.

Flying When this creature enters, investigate X times, where X is the number of opponents you have. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") Whenever you draw your second card each turn, create a 1/1 white Spirit creature token with flying.

This creature enters with X +1/+1 counters on it. When this creature dies, create a 1/1 green Snake creature token for each +1/+1 counter on it. Morph {3}{G}{G} As this creature is turned face up, put five +1/+1 counters on it.

Face-down creatures get +1/+1. {2}{U}: Turn target face-down creature face up.

As this creature enters, turn all other nontoken creatures face down. (They're 2/2 creatures.) Ixidron's power and toughness are each equal to the number of face-down creatures on the battlefield.

Tokens you control have "{T}: Add {G}." Choose a Background (You can have a Background as a second commander.)

When this creature is turned face up, counter all abilities your opponents control. Megamorph {1}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

{2}: Regenerate this creature. Morph {G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Morph {2}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, you may turn target creature with a morph ability face down.

{3}{U}{U}: Turn this creature face down. Morph {1}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, copy target instant or sorcery spell. You may choose new targets for that copy.

Flying {1}: This creature becomes the creature type of your choice until end of turn. Morph {3}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Morph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, destroy target artifact or enchantment.

Disguise {G} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.) When this creature is turned face up, search your library for a land card with a basic land type, reveal it, put it into your hand, then shuffle.

This creature gets +2/+2 for each face-down creature on the battlefield. Morph {3}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

{T}: Add {C}. Spend this mana only to cast a face-down creature spell, pay a mana cost to turn a manifested creature face up, or pay a morph cost. (A megamorph cost is a morph cost.)

Whenever this creature deals combat damage to a player, that player exiles the top ten cards of their library. Morph {2}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Whenever another permanent you control is turned face up, if it's a creature, put two +1/+1 counters on it. Megamorph {3}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Artifacts you control are Clues in addition to their other types and have "{2}, Sacrifice this artifact: Draw a card." Whenever you sacrifice a Clue, target creature can't be blocked this turn.

Flying As long as you control four or more artifacts, this creature has hexproof. (It can't be the target of spells or abilities your opponents control.) Tap two untapped artifacts you control: Draw a card.

Indestructible As long as your devotion to blue is less than five, Thassa isn't a creature. At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control. {3}{U}: Tap another target creature.

Landfall — Whenever a land you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") Whenever you sacrifice a Clue, put a +1/+1 counter on this creature.

Whenever this creature or another artifact you control enters, you may draw a card. If you do, discard a card. {2}: Put target card from your graveyard on the bottom of your library.

Whenever this creature deals combat damage to a player, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") Disguise {3}{G/U}{G/U} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)

Morph {2}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, counter target spell.

When this enchantment enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") Whenever you sacrifice a Clue, target player mills three cards.

Face-down creature spells you cast cost {1} less to cast. {1}{G}: Turn this enchantment face down. (It becomes a 2/2 creature.)

At the beginning of your end step, you may manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.) Exile a face-down permanent you control face up: You may play that card this turn. (You still pay its costs. Timing rules still apply.)

Face-down creatures you control get +0/+1. Whenever a permanent you control is turned face up, draw a card.

Whenever a face-down creature you control enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle. Whenever a permanent you control is turned face up, if it's a creature, it gets +2/+2 until end of turn.

Whenever you cast a colorless creature spell, manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.) Whenever you attack with creatures with total power 6 or greater, you may turn a face-down creature you control face up.