Counter Priority: ⭐️⭐️⭐️⭐️
Summary: The boss's basic attack has a chance to inflict Poison. It is always under Attack Penalty, and each debuff provides it with Corruption stacks.
Countermeasures: Reduce the number of debuff-type heroes to prevent the boss from stacking too much Corruption. Alleviate survival pressure via Defense Up/Damage Reduction.[Putrid Breath]
Counter Priority: ⭐️⭐️⭐️
Summary: Performs a global attack and inflicts Poison and Recharge Speed Penalty. The number of Poison stacks inflicted increases with the boss's Corruption stacks.
Countermeasures: Deploy support heroes such as Acilia, Mithrasea, and Catherine to provide Debuff Dispelling/Debuff Immunity to the entire team.[Rotting Assault]
Counter Priority: ⭐️⭐️
Summary: Inflicts 2 of the boss's debuffs to a random target, and deals AOE damage centered on that target. The number of targets increases with the boss's Corruption stacks.
Countermeasures: Spread out to prevent heroes from taking damage multiple times. 
[Greedy Hunt]
Counter Priority: ⭐️⭐️⭐️⭐️⭐️
Summary: Devours the current target, dealing damage over time and restoring HP based on the damage dealt. The more stacks of Poison the target has, the more HP the boss restores. The devouring effect ends after the boss takes a certain amount of damage.
Countermeasures: Promptly provide tank heroes with Debuff Dispelling/Debuff Immunity, and cast damage dealers' ultimate skills to end the devouring effect as quickly as possible, preventing the boss from restoring too much HP. Alternatively, deploy Thia to grant Invisibility to allies, making the boss to lose its current target.
 The main challenge of clearing the Grave of Rot lies in two aspects. First, the boss can continuously inflict Poison, making it harder for the team to survive. Second, the boss has high HP and restoration capability, which tests the team's damage output.Since the boss has multiple ways to inflict debuffs, it is recommended to deploy 2 heroes skilled in Debuff Dispelling/Debuff Immunity to counter.
For damage output, prioritize heroes with strong single-target damage from schools like Dauntless and Wild.
At difficulty 15 and above, the boss will be under an undispellable Attack Penalty. If survival pressure remains high, alleviate it through Defense Up/Damage Reduction.Summary: The trio of healers — Nathaniel, Thia, and Catherine — offers solid support for the team's survivability. Alternate casting Thia's and Catherine's ultimate skills to maintain Debuff Immunity for all allies. Since this lineup consists only of ranged heroes, Thia's ultimate skill will make the entire team Invisible, making the boss's [Greedy Hunt] lose devourable targets.
 Summary: If the main damage dealer is a melee hero, replacing Thia with Acilia can still work with Catherine to maintain Debuff Immunity for the team. With shields and Damage Reduction from Felosia, Acilia will take minimal damage from the boss's [Greedy Hunt]. Finally, pair them with any two damage dealers you trust the most, and you'll be able to clear the Grave of Rot at the fastest speed.