If I attack an occupied battlefield with Chemtech Enforcer and my opponent plays Gust, does Assault 2 trigger before the reaction?

Ruling: Assault is a passive effect that happens immediately at the start of showdown and cannot be reacted to, so Gust would not work against it during combat. However, if the battlefield was empty (no combat), you would not get the Assault +2 and Gust would work.

Sequence:

• Assault applies immediately upon the unit becoming an attacker at start of showdown
• Attacker triggers go on the initial chain
• Defender triggers go on the initial chain
• Attacker gets priority to respond
• Defender gets priority to respond

Nuances:

• "While" and "if" are passive effects that do not go on the stack and cannot be reacted to
• "When" and "at" are triggers that go on the stack and can be reacted to
• Shield works the same way as Assault (passive effect for defenders)