If equipped creature would be dealt damage, prevent that damage and put that many +1/+1 counters on it.
Equip

Create three 1/1 green Elf Warrior creature tokens.
Reinforce 3— (, Discard this card: Put three +1/+1 counters on target creature.)

Destroy target noncreature permanent. If you control a Treefolk, draw a card.

Exile target permanent, then put it into its owner's hand. That player discards that card, then puts it on top of their library. Then they put it onto the battlefield.

Exile all creatures and Spacecraft.

Flying, lifelink
This creature gets +4/+4 as long as you have 25 or more life.

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

This creature can't be blocked as long as it's attacking alone.
Whenever this creature deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

This spell costs less to cast if you have eight or more instant and/or sorcery cards in your graveyard.
Ward
Magecraft — Whenever you cast or copy an instant or sorcery spell, target creature has base power and toughness 8/8 until end of turn.

Creatures you control have double strike.

: Add .
: Add or . Activate only if you control a Swamp.

The next creature card you play this turn can be played as though it had flash.
Draw a card.

Whenever you gain life, put a charge counter on Excalibur II.
Equipped creature gets +1/+1 for each charge counter on Excalibur II.
Equip

Flying
When Smaug enters, create X tapped Treasure tokens, where X is the number of artifacts your opponents control.
Whenever you cast a spell, if mana from a Treasure was spent to cast it, you draw a card and lose 1 life.

Sacrifice this creature: Add .

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Destroy all creatures. If the gift was promised, return a creature card put into your graveyard this way to the battlefield under your control.

When this Case enters, discard a card, then draw two cards.
To solve — You have no cards in hand. (If unsolved, solve at the beginning of your end step.)
Solved — At the beginning of your upkeep, discard your hand, then draw two cards.

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, return target nonbattle permanent card from your graveyard to the battlefield.

(: Add .)

+2: Each opponent loses 1 life. You gain life equal to the life lost this way.
−2: Create a 5/5 black Demon creature token with flying. You lose 2 life.
−8: You get an emblem with ", Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."
Ob Nixilis of the Black Oath can be your commander.