Katerina of Myra's Marvels

As Katerina of Myra's Marvels enters the battlefield, choose a letter.
Whenever you cast a spell whose name begins with the chosen letter, create a white 2/2 Cat creature token with flying.
Partner (You can have two commanders if they both have partner.)

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Hardy of Myra's Marvels

As Hardy of Myra's Marvels enters the battlefield, choose a number.
Whenever you cast a spell with the chosen number of lines of flavor text, put that many +1/+1 counters on target creature.
Partner (You can have two commanders if both have partner.)

Greatest Show in the Multiverse

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
As an additional cost to cast this spell, exile five instant and/or sorcery cards you own with the same artist and different names from outside the game.
I, II, III — Choose one of the exiled cards at random. You may cast it without paying its mana cost.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Fluros of Myra's Marvels

As Fluros of Myra's Marvels enters the battlefield, choose a number greater than 0.
Whenever you cast a spell with power, toughness, or loyalty equal to the chosen number, target artifact or creature becomes an artifact creature with base power and toughness X/X until end of turn, where X is the chosen number.
Partner

Nocturno of Myra's Marvels

As Nocturno of Myra's Marvels enters the battlefield, choose a word with five or more letters.
Whenever you cast a spell with the chosen word in its rules text, you draw a card and you lose 2 life.
Partner (You can have two commanders if both have partner.)

Ignacio of Myra's Marvels

As Ignacio of Myra's Marvels enters the battlefield, choose armor, blood, book, bottle, fang, fire, scroll, spear, sword, or water.
Whenever you cast a spell with the chosen object in its art, create two Treasure tokens.
Partner (You can have two commanders if both have partner.)

Temple Garden

({T}: Add {G} or {W}.)
As Temple Garden enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.