Hour of Eternity — ruling 1

There are many important moments in the story, but the most crucial—called “story spotlights”—are shown on cards. These cards have the Planeswalker symbol in their text box; this symbol has no effect on gameplay. You can read more about these events in the official Magic fiction at http://www.mtgstory.com.

Hour of Eternity — ruling 2

Each token copies exactly what was printed on the original card and nothing else, except the characteristics it specifically modifies. It doesn't copy any information about the object the card was before it was put into your graveyard.

Hour of Eternity — ruling 3

The tokens are Zombies instead of their other types (unlike Zombies created by an eternalize ability) and are black instead of their other colors. Their power and toughness are 4/4. These are copiable values of the tokens that other effects may copy.

Hour of Eternity — ruling 4

Unlike the tokens created by an eternalize ability, the tokens have the mana cost and thus mana value of the cards they're copying.

Hour of Eternity — ruling 5

If a card copied by one of the tokens had any “when [this permanent] enters the battlefield” abilities, then the token also has those abilities and will trigger them when it's created. Similarly, any “as [this permanent] enters the battlefield” or “[this permanent] enters the battlefield with” abilities that the token has copied will also work.

Hour of Eternity : règles, fonctionnement et interactions (MTG)

Hour of Eternity 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

Exile X target creature cards from your graveyard. For each card exiled this way, create a token that's a copy of that card, except it's a 4/4 black Zombie.

How it works : Hour of Eternity

Original English text — Wizards of the Coast / Scryfall

#1January 19, 2018· Wizards of the Coast
There are many important moments in the story, but the most crucial—called “story spotlights”—are shown on cards. These cards have the Planeswalker symbol in their text box; this symbol has no effect on gameplay. You can read more about these events in the official Magic fiction at http://www.mtgstory.com.
No other card is named in this ruling.
#2July 14, 2017· Wizards of the Coast
Each token copies exactly what was printed on the original card and nothing else, except the characteristics it specifically modifies. It doesn't copy any information about the object the card was before it was put into your graveyard.
Card named in this ruling
Copy
#3July 14, 2017· Wizards of the Coast
The tokens are Zombies instead of their other types (unlike Zombies created by an eternalize ability) and are black instead of their other colors. Their power and toughness are 4/4. These are copiable values of the tokens that other effects may copy.
Card named in this ruling
Copy
#4July 14, 2017· Wizards of the Coast
Unlike the tokens created by an eternalize ability, the tokens have the mana cost and thus mana value of the cards they're copying.
Card named in this ruling
Copy
#5July 14, 2017· Wizards of the Coast
If a card copied by one of the tokens had any “when [this permanent] enters the battlefield” abilities, then the token also has those abilities and will trigger them when it's created. Similarly, any “as [this permanent] enters the battlefield” or “[this permanent] enters the battlefield with” abilities that the token has copied will also work.
No other card is named in this ruling.