Ward
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

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

Affinity for artifacts (This spell costs less to cast for each artifact you control.)
Artifact creature spells you cast have affinity for artifacts. (They cost less to cast for each artifact you control.)

Draw a card for each creature you control.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Up to one target creature can't block for as long as you control this Saga. The Ring tempts you.
II — Search your library for a Mountain card, put it onto the battlefield, then shuffle.
III — Create Smaug, a legendary 6/6 red Dragon creature token with flying, haste, and "When Smaug dies, create fourteen Treasure tokens."

Ward
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Flash (You may cast this spell any time you could cast an instant.)
When Venser enters, return target spell or permanent to its owner's hand.

Enchant creature
When this Aura enters, if enchanted creature has flying, this Aura deals 2 damage to that creature and this Aura gains "Enchanted creature loses flying."

, : Create a Food token. (It's an artifact with ", , Sacrifice this token: You gain 3 life.")
Whenever you sacrifice a Food, create a tapped Treasure token. (It's an artifact with ", Sacrifice this token: Add one mana of any color.")

: Add .

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.
Equip commander
Equip

Trance — At the beginning of combat on your turn, mill two cards. Terra gains flying until end of turn.
Whenever Terra deals combat damage to a player, you may pay . When you do, return target creature card with power 3 or less from your graveyard to the battlefield tapped.

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
, : Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

This land enters with three mining counters on it.
, Remove a mining counter from this land: Add one mana of any color. If there are no mining counters on this land, sacrifice it.

Landfall — Whenever a land you control enters, you get an experience counter.
Whenever you attack, earthbend X, where X is the number of experience counters you have. (Target land you control becomes a 0/0 creature with haste that's still a land. Put X +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

At the beginning of your end step, exile target creature you control, then return it to the battlefield under its owner's control. Then if it's the first end step of the turn, there is an additional end step after this step.

When you cast this spell, draw four cards.
Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents of their choice.)
When Kozilek is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

, , Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for them.)

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.