cr:7.2.3b

The controller of the attack-target and their hero become the “defending hero” until the active chain link resolves or the combat chain closes. If an effect of a source on the chain link refers to the defending hero, it refers to that hero until the combat chain closes.

Example: Exude Confidence has the text “If this isn’t defended by a card with greater or equal {p}, the defending hero can’t play or activate instants and defense reactions,” which is an effect that refers to the defending hero of the chain link where Exude Confidence the active-attack. If the next attack has a different attack-target, Exude Confidence’s effect will still refer to that hero.