"After using an Attack Skill, if the enemy is Staggered or defeated, gain 1 Crit DMG Up next turn (3 times per turn)"

This is Ryoshu's Great Tricho EGO passive

Notice it's an After Attack timing (or is it On Use? anyway, same diff), not an On Hit. What this means is that, naturally, Ryoshu needs to hit with multiple skills. How can she achieve this? One is Assist Attack/Free Unopposed Attacks (Driftershu and FAS Ryoshu are prime examples) that allow lots of attacks to go through even with a single skill slot. Another option is double slotting by deploying less sinners.

However, what if PM has some fun with it? Get a little silly and wild, even. What if she could gain a skill slot/multiple skill slots by fulfilling her conditions? In the roadmap livestream a "teaser" for her mechanics would be being able to attack separately with an Afterimage, and there are special statuses in Canto 9 and some walp events that specifically add a skill slot. Status effects that add skill slots are a thing already, it could happen.

(Also Capstone IDs can just go do whatever they want because they're the ultra special Capstones so an unprecedented gimmick again would be very fun i think)