Well of Ideas

When this enchantment enters, draw two cards.
At the beginning of each other player's draw step, that player draws an additional card.
At the beginning of your draw step, draw two additional cards.

Kami of the Crescent Moon

At the beginning of each player's draw step, that player draws an additional card.

Koth of the Hammer

+1: Untap target Mountain. It becomes a 4/4 red Elemental creature until end of turn. It's still a land.
−2: Add {R} for each Mountain you control.
−5: You get an emblem with "Mountains you control have '{T}: This land deals 1 damage to any target.'"

Neera, Wild Mage

Whenever you cast a spell, you may put it on the bottom of its owner's library. If you do, reveal cards from the top of your library until you reveal a nonland card. You may cast that card without paying its mana cost. Then put all revealed cards not cast this way on the bottom of your library in a random order. This ability triggers only once each turn.

Folio of Fancies

Players have no maximum hand size.
{X}{X}, {T}: Each player draws X cards.
{2}{U}, {T}: Each opponent mills cards equal to the number of cards in their hand.

Minds Aglow

Join forces — Starting with you, each player may pay any amount of mana. Each player draws X cards, where X is the total amount of mana paid this way.

Deathforge Shaman

Multikicker {R} (You may pay an additional {R} any number of times as you cast this spell.)
When this creature enters, it deals damage to target player or planeswalker equal to twice the number of times it was kicked.

Cloven Casting

Whenever you cast a multicolored instant or sorcery spell, you may pay {1}. If you do, copy that spell. You may choose new targets for the copy.

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Mirrodin Besieged

As this enchantment enters, choose Mirran or Phyrexian.
• Mirran — Whenever you cast an artifact spell, create a 1/1 colorless Myr artifact creature token.
• Phyrexian — At the beginning of your end step, draw a card, then discard a card. Then if there are fifteen or more artifact cards in your graveyard, target opponent loses the game.

Tibalt, the Fiend-Blooded

+1: Draw a card, then discard a card at random.
−4: Tibalt deals damage equal to the number of cards in target player's hand to that player.
−6: Gain control of all creatures until end of turn. Untap them. They gain haste until end of turn.

Atemsis, All-Seeing

Flying
{2}{U}, {T}: Draw two cards, then discard a card.
Whenever Atemsis deals damage to an opponent, you may reveal your hand. If cards with at least six different mana values are revealed this way, that player loses the game.