When Abdel Adrian, Gorion's Ward enters the battlefield, exile any number of other nonland permanents you control until Abdel Adrian leaves the battlefield. Create a 1/1 white Soldier creature token for each permanent exiled this way.

Choose a Background (You can have a Background as a second commander.)

Whenever another nontoken creature enters the battlefield under your control, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Flying

Whenever another permanent you control leaves the battlefield, if it had counters on it, investigate. (Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card.")

When Charming Prince enters the battlefield, choose one --

• Scry 2.

• You gain 3 life.

• Exile another target creature you own. Return it to the battlefield under your control at the beginning of the next end step.

Commander creatures you own have "At the beginning of your end step, exile up to one target tapped creature you control, then return it to the battlefield under its owner's control."

Landfall -- Whenever a land enters the battlefield under your control, choose one --

• Create a 2/2 white Cat Beast creature token.

• Put a +1/+1 counter on each creature you control. Those creatures gain vigilance until end of turn.

Alliance -- Whenever another creature enters the battlefield under your control, choose one that hasn't been chosen this turn --

• Put a +1/+1 counter on Gala Greeters.

• Create a tapped Treasure token.

• You gain 2 life.

Engulf -- When Gelatinous Cube enters the battlefield, exile target non-Ooze creature an opponent controls until Gelatinous Cube leaves the battlefield.

Dissolve -- {X}{B}: Put target creature card with mana value X exiled with Gelatinous Cube into its owner's graveyard.

Whenever Golden Argosy attacks, exile each creature that crewed it this turn. Return them to the battlefield tapped under their owner's control at the beginning of the next end step.

Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Whenever one or more +1/+1 counters are put on Herd Baloth, you may create a 4/4 green Beast creature token.

Whenever one or more cards are put into exile from your hand or a spell or ability you control exiles one or more permanents from the battlefield, put that many +1/+1 counters on Hero of Bretagard.

As long as Hero of Bretagard has five or more counters on it, it has flying and is an Angel in addition to its other types.

As long as Hero of Bretagard has ten or more counters on it, it has indestructible and is a God in addition to its other types.

If you control two or more other lands, Lair of the Hydra enters the battlefield tapped.

{T}: Add {G}.

{X}{G}: Until end of turn, Lair of the Hydra becomes an X/X green Hydra creature. It's still a land. X can't be 0.

Exile target creature. At the beginning of the next end step, return that card to the battlefield under its owner's control with a +1/+1 counter on it.

Commander creatures you own have "This creature enters the battlefield with an additional +1/+1 counter on it" and "Other creatures you control enter the battlefield with an additional +1/+1 counter on them."

Whenever a creature enters the battlefield under your control, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

When Seasoned Dungeoneer enters the battlefield, you take the initiative.

Whenever you attack, target attacking Cleric, Rogue, Warrior, or Wizard gains protection from creatures until end of turn. It explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)

I, II -- Until your next turn, creatures you control gain "{T}: Add one mana of any color."

III -- Put a +1/+1 counter on each creature you control. Those creatures gain vigilance, trample, and indestructible until end of turn.

When Spirited Companion enters the battlefield, draw a card.

Stirring Wildwood enters the battlefield tapped.

{T}: Add {G} or {W}.

{1}{G}{W}: Until end of turn, Stirring Wildwood becomes a 3/4 green and white Elemental creature with reach. It's still a land.

Whenever you attack, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Whenever you sacrifice a Clue, venture into the dungeon. (Enter the first room or advance to the next room.)

Vigilance

When Topiary Stomper enters the battlefield, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Topiary Stomper can't attack or block unless you control seven or more lands.

When Touch the Spirit Realm enters the battlefield, exile up to one target artifact or creature until Touch the Spirit Realm leaves the battlefield.

Channel -- {1}{W}, Discard Touch the Spirit Realm: Exile target artifact or creature. Return it to the battlefield under its owner's control at the beginning of the next end step.

When Wood Elves enters the battlefield, search your library for a Forest card, put that card onto the battlefield, then shuffle.