Genshin Impact
Nemesis of Coppelius, strategies, weak points, and achievements
Defeat the Icewind Suite: Duality, Side B.

Icewind Suite is a unique Boss in the way that you need to talk to a nearby character to choose which version of the Boss fight, each giving different rewards; Nemesis of Coppelius gives Shivada Jade (Cryo) and Artificed Spare Clockwork Component — Coppelius.
Icewind Suite Location

Choose "Try Nemesis of Coppelius"

Weak Point
Icewind Suite does not have a specific weakness, but you can interrupt them. In Nemesis of Coppelius, you need to use Ousia (Dark Glow) three times during the Climax (dancing in the center) to interrupt them and stun them for a few seconds.
Strategy
During the Icewind Suite Boss battle, their attacks will do Cryo and Anemo Damage regardless of version and will have high resistance to these Elements; Nemesis of Coppelius focuses more on Anemo attacks.
If you bring Ousia characters, you can stun them whenever they start the Climax, a phase where they dance in the center of the stage, which happens 30 seconds after starting the fight and again after the previous Climax ends.
Coppelius Summons a Cryo shield during this time, Pyro is one of the fastest ways to remove it, but a single Ousia attack can destroy it.
Achievements
Icebound Oath
Use an Ousia attack to remove the shield that Coppelius deploys during the performance's climax.
You can get this achievement easily, just bring an Ousia character.
The Power of Science is Staggering!
Complete one form of the "Icewind Suite" challenge in Co-Op Mode.