When attacking a Nine-Tailed Fox player's unit with Yasuo, Remorseful, what is the order that their triggered effects enter the chain?

Question

Accepted Answer

Both abilities (Yasuo, Remorseful’s “when I attack…” trigger and Nine-Tailed Fox’s “when I are attacked/defended…” trigger) trigger at the same time. The attacker's (active player’s) triggered ability is placed on the chain first, then the defender’s; because the chain resolves last-in/first-out, Nine-Tailed Fox’s trigger will resolve before Yasuo, Remorseful’s. [327] [359.3.f.4]

When Yasuo, Remorseful attacks a Nine-Tailed Fox unit, both triggered abilities trigger simultaneously. Place the active player’s (attacker’s) trigger on the chain first, then the defending player’s trigger; thus Nine-Tailed Fox’s triggered effect will resolve before Yasuo, Remorseful’s. [327] [359.3.f.4]

Attack is declared: both Yasuo, Remorseful’s “when I attack” and Nine-Tailed Fox’s “when I am attacked” triggers trigger simultaneously and become pending triggered abilities. [359.3.f.4] [359.3.f.2] Place triggered abilities on the chain following the Chains conventions: the active player's triggered ability is placed on the chain first, then the non-active player's. [327] Players finalize choices/costs for each pending chain item as they are placed per the finalization rules/FAQ. [FAQ:unleashed#2] Stack resolves last-in/first-out, so the defending player’s (Nine-Tailed Fox) trigger resolves before the attacking player’s (Yasuo, Remorseful) trigger.

If one of the triggered abilities has an additional conditional that is not met during finalization (per [FAQ:unleashed#2]), that ability will not become a finalized chain item even though it initially triggered. If Yasuo, Remorseful or Nine-Tailed Fox changes controllers or moves zones in reaction before their triggers resolve, the referenced terms like “enemy” or “here” are checked as specified by the triggered ability’s reference rules and may cause the resolving effect to mistarget or behave differently. [359.3.f.4] [359.3.f.2] If both triggered abilities are controlled by the same player (e.g., control changes), that player will choose the order they are placed on the chain (standard simultaneous-trigger controller-ordering — see Chains). [327] If one of the triggers requires a target and its target becomes illegal before finalization or resolution, it may be unable to finalize or may mistarget when resolving. [FAQ:unleashed#2] [359.3.f.2]

When you declare an attack with Yasuo, Remorseful and that attack triggers both his "when I attack" ability and Nine-Tailed Fox’s triggered ability for being attacked, those triggered abilities occur at the same time and become pending triggered abilities on the chain. The Chains/trigger placement convention places the active player’s triggered abilities onto the chain first, then the non-active player’s. Therefore you place the attacking player’s (Yasuo, Remorseful) triggered ability on the chain first and then place the defending player’s (Nine-Tailed Fox) triggered ability on top of it; because the chain resolves last-in/first-out, Nine-Tailed Fox’s trigger will resolve before Yasuo, Remorseful’s. [327] [359.3.f.4]

Be mindful of finalization and conditional text: a triggered ability may have extra conditionals or costs that must be finalized when that trigger is placed on the chain (see [FAQ:unleashed#2]). Also, text like “here,” “enemy,” or other referenced information is checked at the times specified by the triggered-ability reference rules; changes of zone or control in reaction can cause a trigger to mistarget or otherwise behave differently when it resolves. Examples in the rules show Yasuo, Remorseful’s attack trigger remaining valid even if he changes controllers after the trigger is placed ([359.3.f.4]) and also show that moving the source away from the referenced location can cause mistargeting ([359.3.f.2]).

Because the provided Core Rules context does not include the exact printed text for Nine-Tailed Fox or the explicit simultaneous-trigger placement paragraph, I used the Chains convention and the Yasuo examples in the Core Rules as the most defensible interpretation. If your actual card text or a locally-applied rule changes the standard simultaneous-trigger ordering, that could change the result.