Interstice: Discarded Image (Boss) with Trial Characters - Shattered Illusion | Honkai Impact 3
All challenges cleared with Trial characters only in boss stage (Discarded Image) of Interstice Exploration - Shattered Illusion.
HoS spear and sword combo does affect the volleyball, make use of it !! The volleyball deals huge damage to the boss upon contact with it.
You get ether energy each time you take out one life (star under HP bar) of the boss so feel free to backstab (using Riemann Stealth) to help whittle down the boss's HP faster for the first 2 life.
The little Homu and Homei summoned late game can only be fast killed with Riemann Stealth so make sure you keep some ether energy for them (Riemann Stealth duration is enough to kill both of them in one active cast, even if they're spawned apart, I managed to do it in the dozen retries before this XD)
**Important - you have to kill the two little ones before you can kill the big Homu Magician (King)
Backstab = hitting the enemies from the back within the purple box when you have Riemann Stealth activated (kinda like time fracture). Sometimes the game doesn't register the backstab so you might have to run back and forth a bit.
Might take a few retries on this stage but GOOD LUCK everyone!