Enchant artifact
At the beginning of the upkeep of enchanted artifact's controller, this Aura deals 1 damage to that player.

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Players can't untap more than one creature during their untap steps.

Other Merfolk get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

First strike

Each player chooses a number of lands they control equal to the number of lands controlled by the player who controls the fewest, then sacrifices the rest. Players discard cards and sacrifice creatures the same way.

At the beginning of each player's upkeep, this enchantment deals X damage to that player, where X is the number of untapped lands they controlled at the beginning of this turn.

If you would draw a card during your draw step, instead you may skip that draw. If you do, until your next turn, you can't be attacked except by creatures with flying and/or islandwalk.

White creatures get +1/+1.

, : Untap target creature.

Return all artifacts target player owns to their hand.

: This creature gets +1/+0 until end of turn.

, Discard a card at random: Target creature gets +2/+2 until end of turn.

Tap all lands target player controls and that player loses all unspent mana.

Enchant artifact an opponent controls
Whenever enchanted artifact becomes tapped, choose one —
• This Aura deals 1 damage to target player or planeswalker.
• Target player gains 1 life.

You may spend white mana as though it were red mana.

When this creature attacks or blocks, at end of combat, sacrifice it and it deals 5 damage to you.
, : Return target permanent that isn't enchanted to its owner's hand.

: Until your next upkeep, target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.

Other Goblins get +1/+1 and have mountainwalk.

When this creature dies, you gain 2 life.

The next time a source of your choice would deal damage to you this turn, prevent that damage. You gain life equal to the damage prevented this way.

Whenever you cast an enchantment spell, you may draw a card.

Other Zombie creatures have swampwalk. (They can't be blocked as long as defending player controls a Swamp.)
Other Zombies have ": Regenerate this permanent."

: Destroy target tapped creature.

: Target creature other than this creature has base power and toughness 0/2 until end of turn.

Blue creatures don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player may choose any number of tapped blue creatures they control and pay for each creature chosen this way. If the player does, untap those creatures.

, : Untap target attacking creature you control. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Whenever this creature deals damage, you gain that much life.

Destroy X target Mountains. Volcanic Eruption deals damage to each creature and each player equal to the number of Mountains put into a graveyard this way.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

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

All Forests are 1/1 creatures that are still lands.

Whenever a player taps a land for mana, this enchantment deals 1 damage to that player.

, Pay 2 life: Draw a card.

, : Destroy target black permanent.