You may spend mana as though it were mana of any color to activate abilities of creatures you control.

Creatures you control with +1/+1 counters on them have all activated abilities of all creature cards exiled with Agatha's Soul Cauldron.

{T}: Exile target card from a graveyard. When a creature card is exiled this way, put a +1/+1 counter on target creature you control.

Flying

Whenever Ancient Brass Dragon deals combat damage to a player, roll a d20. When you do, put any number of target creature cards with total mana value X or less from graveyards onto the battlefield under your control, where X is the result.

Flying

Whenever Ancient Copper Dragon deals combat damage to a player, roll a d20. You create a number of Treasure tokens equal to the result.

Flying

Whenever Ancient Gold Dragon deals combat damage to a player, roll a d20. You create a number of 1/1 blue Faerie Dragon creature tokens with flying equal to the result.

Flying

Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

You can't cast permanent spells.

{4}, {T}: Add {W}{U}{B}{R}{G}. When you cast your next spell this turn, exile cards from the top of your library until you exile an instant or sorcery card with lesser mana value. Until end of turn, you may cast that card without paying its mana cost. Put each other card exiled this way on the bottom of your library in a random order.

For Mirrodin! (When this Equipment enters the battlefield, create a 2/2 red Rebel creature token, then attach this to it.)

Equipped creature gets +2/+2.

Whenever equipped creature attacks, if it's the first combat phase of the turn, untap each attacking creature. After this phase, there is an additional combat phase.

Equip {3}{R}

For Mirrodin! (When this Equipment enters the battlefield, create a 2/2 red Rebel creature token, then attach this to it.)

Equipped creature gets +2/+2.

Whenever equipped creature attacks, if it's the first combat phase of the turn, untap each attacking creature. After this phase, there is an additional combat phase.

Equip {3}{R}

Vigilance, trample, haste

{W}{U}{B}{R}{G}: You may play target Elemental card from your graveyard without paying its mana cost.

Whenever an opponent casts a creature spell, that player loses 2 life unless they pay {2}.

Changeling (This card is every creature type.)

As Morophon, the Boundless enters the battlefield, choose a creature type.

Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.

Other creatures you control of the chosen type get +1/+1.

Flying

When Niv-Mizzet Reborn enters the battlefield, reveal the top ten cards of your library. For each color pair, choose a card that's exactly those colors from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order.

Flying, hexproof from monocolored

Each instant and sorcery card in your graveyard that's exactly two colors has jump-start. (You may cast that card from your graveyard by discarding a card in addition to paying its other costs. Then exile it.)

If you would lose unspent mana, that mana becomes black instead.

At the beginning of your precombat main phase, look at the top card of your library. You may reveal that card if it has three or more colored mana symbols in its mana cost. If you do, add three mana in any combination of its colors and put it into your hand. If you don't reveal it, put it into your hand.

({2/W} can be paid with any two mana or with {W}. This card's mana value is 10.)

Other Scarecrow creatures you control get +1/+1.

Whenever another Scarecrow enters the battlefield under your control, destroy target permanent.

Flying

{2}: Search your library for a Dragon permanent card and put it into your graveyard. If you do, Scion of the Ur-Dragon becomes a copy of that card until end of turn. Then shuffle.

Deathtouch

Whenever you draw a card, you gain 2 life.

Whenever an opponent draws a card, they lose 2 life.

Deathtouch

Whenever you draw a card, you gain 2 life.

Whenever an opponent draws a card, they lose 2 life.

The "legend rule" doesn't apply to Slivers you control.

Each Sliver creature card in your graveyard has encore {X}, where X is its mana value.

Encore {5} ({5}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Sliver creatures you control have indestructible. (Damage and effects that say "destroy" don't destroy them.)

All Sliver creatures get +1/+1 for each other Sliver on the battlefield.

{3}: Search your library for a Sliver card, reveal that card, put it into your hand, then shuffle.

{3}: Gain control of target Sliver. (This effect lasts indefinitely.)

{2}: Create a 1/1 colorless Sliver creature token.

This spell costs {1} less to cast for each creature in your party.

{2/U}{2/B}{2/R}{2/G}: Look at the top six cards of your library. You may reveal up to two Cleric, Rogue, Warrior, Wizard, and/or Ally cards from among them and put them into your hand. Put the rest on the bottom of your library in a random order.

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Sliver spells you cast have cascade.

Eminence -- As long as The Ur-Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost {1} less to cast.

Flying

Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.

Flying

When Tiamat enters the battlefield, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle.

Whenever you cast a Myr spell, create a 1/1 colorless Myr artifact creature token.

At the beginning of combat on your turn, untap each Myr you control.

{W}{U}{B}{R}{G}, {T}: Put three +1/+1 counters on each Myr you control. Activate only during your turn.