Passive - [Shield Warrior]
Counter Priority: ⭐️⭐️⭐️⭐️⭐️
Summary: The boss has Shield Form and Sword Form. In Shield Form, basic attacks deal Global Damage. In Sword Stance, basic attacks deal heavy single-target damage.
Countermeasures: Deploy a tank with high survivability to withstand the damage from Sword Form. Use AOE shields and Damage Reduction, and inflict an Attack Penalty on the boss to reduce the pressure on your backline heroes when the boss is in Shield Form.[Berserker's Wrath - Shield Form]
Counter Priority: ⭐️⭐️⭐️⭐️
Summary: Stuns the target farthest from the boss. If the Stun effect fails to apply or is dispelled, the boss enters the Backfire state, reducing its damage dealt and increasing its damage taken.
Countermeasures: It is recommended to stack Resistance on the backline hero farthest from the boss. You can also consider using heroes with the ability of Control Dispelling/Control Immunity.[Devouring Shadows - Shield Form]
Counter Priority: ⭐️⭐️⭐️
Summary: Switches to Sword Form and gains an Attack Up buff.
Countermeasures: Promptly use Buff Dispelling/Buff Prohibition to avoid immense survival pressure.[Berserker's Wrath - Sword Form]
Counter Priority: ⭐️⭐️
Summary: Deals high damage to the single target with the highest Attack.
Countermeasures: Provide timely shields and healing to the hero being attacked. If they cannot withstand the attack, inflict an Attack Penalty on the boss beforehand. 
[Devouring Shadows - Sword Form]
Counter Priority: ⭐️⭐️⭐️⭐️⭐️
Summary: Attacks all targets and dispels all their buffs. The boss gains a permanent Total Damage Bonus based on the number of buffs dispelled. It then switches back to Shield Form and gains a Defense Up buff.
Countermeasures: Avoid granting too many buffs to your team before the boss casts this skill. Use AOE shields and inflict an Attack Penalty to handle the Global Damage after the boss enters Shield Form. If your tank has high survivability, consider using Buff Dispelling after the boss casts this skill to remove both buffs.
 The main difficulty in the Ancient Battlefield lies in surviving the constant global attacks from the boss in Shield Form. To ensure your team's survival, in addition to inflicting an Attack Penalty, you'll also need heroes who can provide consistent AOE healing and shields.
After the boss casts [Devouring Shadows - Sword Form] and switches to Shield Form, you can use Damage Reduction and Defense Up to further alleviate survival pressure.
Additionally, the boss can buff itself and inflict control effects on your team. You'll need to counter this through Buff Dispelling/Buff Prohibition, and by either stacking Resistance on specific heroes or providing Control Dispelling/Control Immunity.
 Summary: You'll need to stack Resistance on Felosia to counter [Berserker's Wrath - Shield Form]. Garius and Frurbath will provide sufficient healing over time for the team. Before the boss switches to Sword Form, use Voresh's ultimate skill to prevent it from gaining an Attack Up buff. While the boss is in Sword Form, use Frurbath to inflict an Attack Penalty. After the boss switches back to Shield Form, use Felosia's ultimate skill to provide Damage Reduction, keeping your team's incoming damage at a safe level. Finally, add a hero with excellent independent combat capabilities like Premtsa to ensure sufficient damage output.
 Summary: Vinyara is highly effective against the Soul Devourer. She doesn't need to stack Resistance and can negate the Stun effect of [Berserker's Wrath - Shield Form] with her passive skill alone. Her ultimate skill can also dispel all of the boss's buffs and inflict an Attack Penalty. By alternating her ultimate skill with Khrysos's, you can keep the boss permanently under an Attack Penalty. Khrysos's AOE shields and Torrin's healing over time provide stable support for the team. Finally, add single-target damage dealers like Felicity and Flora to easily clear the stage.