Herald of the Host

The tokens created by the myriad ability enter the battlefield tapped even though they’ll have vigilance.

Wotc — November 04, 2015

The term “defending player” in the myriad rules (or any other ability of an attacking creature) refers to the player the creature with myriad was attacking at the time it became an attacking creature this combat, or the controller of the planeswalker the creature was attacking at the time it became an attacking creature this combat.

Wotc — November 04, 2015

If the defending player is your only opponent, no tokens are put onto the battlefield.

Wotc — November 04, 2015

You choose whether each token is attacking the player or a planeswalker they control as the token is created.

Wotc — November 04, 2015

Although the tokens enter the battlefield attacking, they were never declared as attackers. Abilities that trigger whenever a creature attacks won’t trigger, including the myriad ability of the tokens. If there any costs to have a creature attack, those costs won’t apply to the tokens.

Wotc — November 04, 2015

The token creatures all enter the battlefield at the same time.

Wotc — November 04, 2015

Each token copies exactly what was printed on the original creature and nothing else. It doesn’t copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, and so on.

Wotc — November 04, 2015

Any enters-the-battlefield abilities of the copied creature will trigger when the token enters the battlefield. Any “as [this permanent] enters the battlefield” or “[this permanent] enters the battlefield with” abilities of the copied creature will also work.

Wotc — November 04, 2015

If myriad creates more than one token for any given player (due to an effect such as the one Doubling Season creates), you may choose separately for each token whether it’s attacking the player or a planeswalker they control.

Wotc — November 04, 2015