Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Whenever Lone Revenant deals combat damage to a player, if you control no other creatures, look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Whenever a spell or ability you control counters a spell, you may create a 1/1 blue Merfolk creature token.
Tap seven untapped Merfolk you control: Counter target spell.

This spell costs less to cast, where X is the total converted mana cost of noncreature artifacts you control.
Sacrifice two artifacts: Return Metalwork Colossus from your graveyard to your hand.

Flying
You may cast Misthollow Griffin from exile.

Create two 1/1 red Elemental creature tokens, then flip a coin. If you win the flip, return Molten Birth to its owner's hand.

When Myr Sire dies, create a 1/1 colorless Myr artifact creature token.

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls with a -1/-1 counter on it dies, you may return that card to the battlefield under your control.

Enchant creature
Enchanted creature has "At the beginning of your upkeep, sacrifice this creature."
When enchanted creature dies, its controller chooses target creature one of their opponents controls. Return Necrotic Plague from its owner's graveyard to the battlefield attached to that creature.

[+1]: Search your library for a card named Nissa's Chosen and put it onto the battlefield. Then shuffle your library.
[+1]: You gain 2 life for each Elf you control.
[−7]: Search your library for any number of Elf creature cards and put them onto the battlefield. Then shuffle your library.

If Nissa's Chosen would die, put it on the bottom of its owner's library instead.

When you cast this spell, target opponent exiles the top four cards of their library, then you may put any number of land cards that player owns from exile onto the battlefield under your control.

Destroy target creature with flying. Its controller gets a poison counter.

This spell costs less to cast for each creature your opponents control.
When Primeval Protector enters the battlefield, put a +1/+1 counter on each other creature you control.

Protection from everything
If Progenitus would be put into a graveyard from anywhere, reveal Progenitus and shuffle it into its owner's library instead.

Target opponent reveals their hand. You choose a nonland card from that player's graveyard or hand and exile it. You may cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.

, , Sacrifice a creature: Destroy target enchantment.

Creatures you control get +2/+0 until end of turn.
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Each player discards their hand, then draws seven cards.
Miracle (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

If an opponent cast a blue spell this turn, you may pay rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Destroy target creature or planeswalker.
Awaken 4— (If you cast this spell for , also put four +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)