Interstice: Bedlam Zone - Condensation (Boss) with Trial Characters | Honkai Impact 3
Steadily and stealthily backstab to victory.
The boss fight in Kolosten: Interstice Exploration - Bedlam Zone - Condensation (Boss stage) using trial characters.
Active Core Skill: Riemann Stealth to make your life easy.
Stealth kill the Scarlet Uriel (the flying mob) to apply debuff on the boss, and then just keep backstabbing the boss to death if you would like, or mix in some rotations.