The six-stage endgame challenge Stygian Onslaught (version 6.7) features three battlefield bosses with unique mechanics and rewards, requiring players to understand mechanics and build optimized, adaptable teams.

For the Lord of the Hidden Depths: Whisperer of Nightmares, expect a Deepdark Shield at 45% max HP; breaking it within 15 seconds stuns the boss, removes 20% HP, and reduces elemental resistance by 60%, while Anglers spawn and the shield takes 300% extra damage from Lunar Reactions and is immune to Physical DMG.

Best teams for the Lord of the Hidden Depths include Lunar Bloom and Lunar Charge setups such as Neffer, Lauma, Columbina, Nahida, or Flins, Ineffa, Columbina, Sucrose, with alternative teams like Zibai/Linnea/COLUMBINA/Illuga.

For the Secret Source Automaton Configuration Device on Battlefield 3, the Nightsoul mechanic requires Natlan-damage to break a tanky shield; recommended teams include Mavuika/Xilonen/Citlali/Bennett, Mavuika/Ororon/Iansan/Chevreuse, and Chasca/Citlali/Iansan/Nicole.

Introductory overview highlights the six-stage endgame and notes three battlefield bosses with varied mechanics, offering multiple optimized team compositions to clear each stage.

Introduction also emphasizes that the Luna VIII update brings the Stygian Onslaught and new boss encounters that reward careful planning and knowledge of mechanics.

Readers are urged to engage with accompanying guides for builds and rotations and to share feedback.

Battlefield 2 strategy emphasizes Lunar Reaction damage; suggested teams include Zibai/Linnea/COLUMBINA/Illuga, Flins/Ineffa/COLUMBINA/Sucrose, and Nefer/Lauma/COLUMBINA/Nahida.

Notes mention buffs to Sandrone and Qiqi and provide substitutions for teams, focusing on endgame optimization for the 6.7 update.

Alternative Battlefield 1 teams lean on superconduct strategies, such as Flins/COLUMBINA/Escoffier/Ineffa, or Skirk/Escoffier/Furina/Fischl (or Ineffa), with a focus on device targeting and superconduct damage.

The Shadow of the Precursor’s Secret Source Matrix of Overseer Network summons four Hydro drones; destroying them removes the Hydro shield and stuns the boss, with Stella Conduct aiding shield break.

General guidance stresses exploiting boss weaknesses with elemental reactions, handling shield mechanics, and capitalizing on windows after shields break or phase transitions, while adapting to character availability and buffs.