Tiamat's Fanatics

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.

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.

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 or the controller of the planeswalker it was attacking at the time the ability resolves. If that creature is no longer attacking, it refers to the player it was last attacking or the controller of the planeswalker it was last attacking.

Any enters-the-battlefield abilities of the copied creature will trigger when the tokens enter the battlefield. Any "as [this permanent] enters the battlefield" or "[this permanent] enters the battlefield with" abilities of the copied creature will also work.