Hi all, just want to share my strategy that uses 4 units to clear The Empress Supreme LGD.

Disclaimer: this strategy is slightly gear dependent but if you can pull it off, it can help you complete the bonus challenge without the hassle of gearing different units every time.

Team composition

- CG Sieghart (or any tank with passive provoke. For magic tank, iNichol can be used if you dont have Rivera)

- Sylvie

- Elena x 2

Two empty slots for fillers (these units are there to throw an elixir or eccentric/entrust/P shield or whatever support they can give)

Gearing

Gearing can be found here.

Brief explanation

- Sieghard: DEF, HP and 100% passive provoke

- Sylvie: generally high eHP. Optional: high LB fill rate.

- Elena: Man-killer, generally high eHP and balanced ATK/MAG build as it is important to kill both adds together.

Sample clear video link

Rotation

Turn 1:

- Elena Starlight Luminous Enervation Way of the Aurora. Note: each Elena targets one add as the light imperil from Luminous Enervation is ST.

- Sieghard physical covers.

- Sylvie Double the Fun! Hop to the Rescue (target Sieghard) Growing Defense

Turn 2:

- Sylvie Triple the Fun! Hop into battle (target better Elena)! Protective Petals Protective Vines.

- Sieghard guards.

- Two Elena LBs. Note: if one of the knights die while the other is still alive, soft reset and try not to fully chain LB to keep both knights alive. Morgana always went crazy and wiped my team if one knight died during the LB turn.

Turn 3:

- Sylvie: Triple the Fun! A Paladin's Duty Gracious Knight Growing Defense or LB (whichever that benefits you more)

- Sieghard: LB

- Elena: Speed of Light Blade of Crystal (target the one with higher HP) Aurora Tempest Aurora Tempest to kill both knights or Aurora Arts Aurora Tempest x 2 as suggested by u/fatcatsings

- Survive Morgana's rampage (there is an element of RNG here as Morgana can do more than 1 AoE and wipe your team. I got unlucky a few times during my test runs of the same team. Thank goodness it's only 5 nrg)

Turn 4:

- Elena: Speed of Light Blade of Crystal x 3 to finish off.