Clash: Artifacts of Chaos
21 Achievements
GOG
Broken Reflection
Defeat Nightmare Gemini
4.2%
How to unlock the Broken Reflection achievement in Clash: Artifacts of Chaos - Definitive Guide
She only spawns once you have defeated all the nightmare dark bosses. You can find her in the town. She isn't to hard dodge her attacks and when she starts spinning her weapon wait till she stops then hit her with a heavy attack or weapon if you have one. It will stun her for a second for you to get a good combo in just repeat and you should have no problem.