When two Auroras resolve (one playing a DeadBloom into battlefield, another playing a dragon), does the dragon's +8 effect resolve before or after the battle/showdown starts?

Ruling: The dragon's +8 effect resolves before the showdown starts. A showdown cannot start while there is an active chain - all triggers must be added to the chain and resolve before the showdown can begin.

Sequence:

• First Aurora resolves, playing DeadBloom into battlefield
• Second Aurora resolves, playing dragon
• Dragon's +8 trigger is added to the chain
• All triggers on the chain resolve
• Only after the chain is empty (open state) can the showdown start

Nuances:

• During cleanup, the game checks if things need to be put on the chain first, then later checks if the state is open and showdown/combat can start
• The order matters: if the dragon came out first, its trigger would go on the chain last and resolve before the second Aurora