Vorthos, Steward of Myth

As Vorthos, Steward of Myth enters, choose a named Magic character.
Each spell you cast with the chosen character in its name, flavor text, or art costs {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.

Hardy of Myra's Marvels

As Hardy of Myra's Marvels enters, 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.)

Fluros of Myra's Marvels

As Fluros of Myra's Marvels enters, 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, 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, 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.)

Myra the Magnificent

Whenever you cast an instant or sorcery spell from your hand, open an Attraction.
{X}, {T}: Exile target instant or sorcery card with mana value X from your graveyard and choose an Attraction you control that doesn't have a midway counter on it. Put a midway counter on it. For as long as that Attraction is on the battlefield, whenever you visit it, copy the exiled card. You may cast the copy without paying its mana cost.

Katerina of Myra's Marvels

As Katerina of Myra's Marvels enters, 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.)