Does Darius count himself as the second card played to trigger his own ability, or does he need to be on the board already?

Ruling: Darius counts himself as a played card. If Darius is your second card played this turn, his ability will trigger and he will ready himself.

Sequence:

• Play your first card
• Play Darius as your second card
• Darius resolves and sees himself as the second card played
• His ability triggers, giving him 2 Might and readying him

Nuances:

• In Riftbound, a card is considered "played" when it resolves, which is why Darius can see himself