Myth Realized — ruling 1

Myth Realized can't attack the turn it enters the battlefield.

Myth Realized — ruling 2

Activating the ability that turns Myth Realized into a creature while it's already a creature will override any effects that set its power or toughness to a specific value. Effects that modify power or toughness without directly setting them to a specific value will continue to apply.

Myth Realized : règles, fonctionnement et interactions (MTG)

Myth Realized is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Whenever you cast a noncreature spell, put a lore counter on this enchantment. : Put a lore counter on this enchantment. : Until end of turn, this enchantment becomes a Monk Avatar creature in addition to its other types and gains "This creature's power and toughness are each equal to the number of lore counters on it."

How it works : Myth Realized

Original English text — Wizards of the Coast / Scryfall

#1February 25, 2015· Wizards of the Coast
Myth Realized can't attack the turn it enters the battlefield.
No other card is named in this ruling.
#2February 25, 2015· Wizards of the Coast
Activating the ability that turns Myth Realized into a creature while it's already a creature will override any effects that set its power or toughness to a specific value. Effects that modify power or toughness without directly setting them to a specific value will continue to apply.
No other card is named in this ruling.