Exile All Hallow's Eve with two scream counters on it.
At the beginning of your upkeep, if this card is exiled with a scream counter on it, remove a scream counter from it. If there are no more scream counters on it, put it into your graveyard and each player returns all creature cards from their graveyard to the battlefield.

: If target Plains is tapped for mana, it produces colorless mana instead of white mana. (This effect lasts indefinitely.)

No more than two creatures can attack each combat.
No more than two creatures can block each combat.

: Target player discards a card at random. Activate only during your turn.

: Create a 1/1 green Wolf creature token named Wolves of the Hunt. It has "bands with other creatures named Wolves of the Hunt." (Any creatures named Wolves of the Hunt can attack in a band as long as at least one has "bands with other creatures named Wolves of the Hunt." Bands are blocked as a group. If at least two creatures named Wolves of the Hunt you control, one of which has "bands with other creatures named Wolves of the Hunt," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Whenever a Mountain an opponent controls becomes tapped, you gain 1 life.

Starting with you, each player may put a permanent card from their hand onto the battlefield. Repeat this process until no one puts a card onto the battlefield.

: Change this creature's base toughness to 1 plus the power of target creature blocking or blocked by this creature. (This effect lasts indefinitely.)

Destroy all black creatures.

, Sacrifice a creature: Return target creature card from your graveyard to the battlefield. Activate only during your upkeep.

Creatures you control get +1/+1 as long as you control no nonartifact, nonwhite creatures.

At the beginning of each player's upkeep, destroy target nonartifact creature that player controls of their choice. It can't be regenerated.

Whenever an opponent casts a creature spell that doesn't share a color with a creature you control, counter that spell unless that player pays , where X is its mana value.

Creatures without flying can't attack.

Flying
, : This creature deals 1 damage to target attacking or blocking creature.

If an opponent who controls at least as many lands as you do would put a land onto the battlefield, that player instead puts that land onto the battlefield then sacrifices a land of their choice.

At the beginning of each player's upkeep, if that player controls a Plains, they gain 1 life.

, : Exile the top card of your library face down.
: Sacrifice this artifact. If you do, discard your hand, then put all cards exiled with this artifact into their owner's hand.
When this artifact leaves the battlefield, put all cards exiled with it into their owner's graveyard.

: Prevent the next 2 damage that would be dealt to target creature this turn.

Whenever a player casts a spell, counter it unless that player pays .

At the beginning of your upkeep, change Halfdane's base power and toughness to the power and toughness of target creature other than Halfdane until the end of your next upkeep.

Cast this spell only before blockers are declared.
Target creature gains first strike until end of turn. If it doesn't have rampage, that creature gains rampage 2 until end of turn. (Whenever the creature becomes blocked, it gets +2/+2 until end of turn for each creature blocking it beyond the first.)

Remove this card from your deck before playing if you're not playing for ante.
, Sacrifice this creature: Target opponent may pay 10 life. If that player doesn't, they reveal a card at random from their hand. Exchange ownership of the revealed card and Tempest Efreet. Put the revealed card into your hand and Tempest Efreet from anywhere into that player's graveyard. This change in ownership is permanent.

As this creature enters, sacrifice any number of untapped Forests.
Wood Elemental's power and toughness are each equal to the number of Forests sacrificed as it entered.

Green creatures you control get +0/+2.

, : Target permanent you control becomes the color of your choice. (This effect lasts indefinitely.)

, : Put a matrix counter on target creature and that creature gains "Remove a matrix counter from this creature: Regenerate this creature." Activate only during your upkeep.

: This creature gets +1/+1 until end of turn.

, : Put a hatchling counter on this artifact.
Sacrifice this artifact: Choose one. Activate only if there are two or more hatchling counters on this artifact.
• You may put a creature card from your hand onto the battlefield.
• Return target creature card from your graveyard to the battlefield.

, : For one spell this turn, you may spend mana as though it were mana of any type to pay that spell's mana cost. (Additional costs are still paid normally.)

Flying
, : Target creature gains flying until end of turn.

Destroy all Forests.

, : The next time a source of your choice would deal damage to you this turn, that damage is dealt to target creature of an opponent's choice instead.

You and target player exchange control of the creature you each control with the greatest mana value. Then exchange control of artifacts the same way. If two or more permanents a player controls are tied for greatest, their controller chooses one of them.

All damage that would be dealt this turn by target sorcery spell is dealt to that spell's controller instead.

Enchant creature
Enchanted creature gets +3/+3.