X can't be greater than the number of players in the game.
Reveal cards from the top of your library until you reveal X land cards. Put those land cards onto the battlefield tapped and the rest on the bottom of your library in a random order.

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
: Add , , or .

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

: Add one mana of any color in your commander's color identity.

: Add .
, : Put target Zombie card from your graveyard on top of your library.

Enchant creature card in a graveyard
When this Aura enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with this Aura." Return enchanted creature card to the battlefield under your control and attach this Aura to it. When this Aura leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Play with the top card of your library revealed.
You may play lands and cast spells from the top of your library.

Other enchantment creatures you control get +1/+1.
, : Copy target activated or triggered ability you control from an enchantment source. You may choose new targets for the copy. (Mana abilities can't be targeted.)

Whenever you put a counter on a creature you control, draw a card. This ability triggers only once each turn.

: Add .
: Add or . This land deals 1 damage to you.

You may cast spells from your hand without paying their mana costs.

: Add .
, Sacrifice this land: Add .

All damage that would be dealt to you is dealt to equipped creature instead.
Equip

Flying, deathtouch
When Dragonlord Silumgar enters, gain control of target creature or planeswalker for as long as you control Dragonlord Silumgar.

Deathtouch
When God-Eternal Rhonas enters, double the power of each other creature you control until end of turn. Those creatures gain vigilance until end of turn.
When God-Eternal Rhonas dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip (: Attach to target creature you control. Equip only as a sorcery.)

Whenever another creature enters, you gain 1 life.

Return target nonland permanent with mana value X to its owner's hand.
Draw a card.

Counter target spell. If the spell is countered this way, exile it with three time counters on it instead of putting it into its owner's graveyard. If it doesn't have suspend, it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, they may play it without paying its mana cost. If it's a creature, it has haste.)

+1: Reveal the top four cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.
0: Put any number of land cards from your hand onto the battlefield tapped.
−3: Create a green Treefolk creature token with reach and "This token's power and toughness are each equal to the number of lands you control."
−8: Return all permanent cards from your graveyard to your hand. You get an emblem with "You have no maximum hand size."