Etemon

Q:What happens if this card's [When Digivolving] effect activates twice and 2 of my opponent's Digimon gain the "[Start of Your Main Phase] This Digimon attacks" effect?

A:The effects trigger at the same time at the start of your opponent's main phase, and an attack is only performed for the effect that activated first. Specifically, after activation has ended for an effect such as the [When Attacking] effect on the Digimon whose effect activated first, and before the counter timing occurs, the effect would activate for the 2nd Digimon that was pending activation, but since the 1st Digimon is already attacking, the effect ends without an attack made. As a result, only the Digimon whose effect was activated first can attack.