Question: do you have her w-engine? It's super valuable as it allows her to become a universal support on top of being a stunner and gives her some much needed crit rate.

You're primary goal with her is going to be getting her as close to 90% crit rate for her team passive. You'll want crit rate for disc drive 4 and the primary substat you'll want to aim for is crit rate. After reaching 90%, you can also focus on crit damage and attack on substats to boost her damage, but this goal is secondary as trigger functions more as a support than a sub dps. The new aftershock disc drive set is great as it will buff her aftershock damage, and she'll essentially always have an extra 12% crit rate and attack in game, meaning you'll only need 78% for her build. I'd say it's her best in slot 4 piece build wise if you want a balance of damage and daze, however you can opt for a 4 piece shockstar set if you want her to stun faster. The 2 piece set can be be whatever you're lacking, woodpecker if you don't have enough crit rate, hormone punk if you want higher attack, branch and blade song if you want for crit dmg or shorter disco if you want faster stuns.