In a showdown, can the defender respond to the attacker's action with another action, and when can the defender use their own action? Also, can counterspells like Defy target earlier spells in the chain or only the most recent one?

Ruling: When entering a showdown as an attacker, you can use an action. The defender cannot respond to this action with another action - they must use a reaction. After the attacker's action resolves, the defender then has the opportunity to activate their own action. Counterspells like Defy can target any earlier spell on the Chain as long as it meets the other conditions, not just the most recent spell.

Sequence:

• Attacker enters showdown and uses an action
• Defender can only respond with a reaction (not an action)
• After attacker's action resolves, defender can activate their own action

Nuances:

• Defy can counter any spell earlier in the chain, not just the most recent one, as long as other targeting conditions are met