This is a guide on how to beat Corrupted Ancient Dragon in The Seven Deadly Sins: Origin (7DSO). Covering Ancient Dragon's location, recommended team, and combat strategies.
All Boss Locations and Strategy
Table of Contents
Corrupted Ancient Dragon Location
Boss Challenge
You can challenge the Corrupted Ancient Dragon from the Boss Challenge in the menu.
Enter with Sufficient Combat Power
In the Boss Challenge against the Corrupted Ancient Dragon, you must deplete the enemy's HP while enduring DoT during the final phase. If your characters are underleveled, the sustained damage may overwhelm you, leading to defeat. It is recommended to challenge the boss with a sufficient margin in your Combat Power Score.
Also Appears as a Story Boss
The Corrupted Ancient Dragon also appears as a boss in Main Story ACT 12. While rewards and stats differ, the core strategy remains largely the same as in the Boss Challenge. Note that the Boss Challenge unlocks after defeating it in the story.
Benefits of Farming the Ancient Dragon
Materials for Engraved Equipment
You can obtain the Bottoms and Belt from the "Revived Nightmare" set, which are required to craft Engraved Equipment. The Top and Combat Boots drop from the Spider Queen's Nest dungeon, so it is recommended to farm both sources.
Required for Meliodas's Longsword
The Dragon's Fire Sac, dropped by the Corrupted Ancient Dragon, is required to craft a Longsword that synergizes well with Meliodas. If you have Meliodas, farming this material is recommended to boost your Combat Power.
Team and Recommended Characters
Sample Party Formation
| DPS | Burst Efficiency Boost | Tank | Healer |
 MeliodasDual Swords |  TristanDual Swords |  GuilaSword and Shield |  TiorehWand |
This setup centers on Meliodas, a Darkness-element DPS hero that exploits the enemy’s weakness. A prolonged battle is expected, so sustain through it with Guila’s Sword and Shield Barrier and Tioreh’s Wand healing. Meliodas with Dual Swords can deal damage while recovering HP, helping offset the DoT in the final phase.
Recommended Characters
| Recommended Character | Reason |
| Meliodas | - A Darkness Burst DPS - His Dual Swords allow him to attack while healing, making him a good match against this enemy. |
 Jericho | - High Burst accumulation and damage. You'll want to use her with Meliodas. |
Due to the enemy’s unique mechanic, managing Burst activations is critical. It is recommended to build a party with Darkness plus other elements. Activating Burst with a different element, then following with Darkness, increases the resistance reduction count by 2.
Basic Strategy for Corrupted Ancient Dragon
What to Know Before the Battle
Remember Its Special Abilities
The Corrupted Ancient Dragon resists Element Damage and Elemental Bursts. Its resistance can be reduced by activating Bursts or applying debuffs, so prioritize entering a Burst state quickly and applying debuffs during the fight.
Move Center to Dodge First Attack
Upon entering the battle area, the Corrupted Ancient Dragon opens with a ranged attack. Move to the center to avoid taking an immediate hit.
Behavior Changes by Remaining HP
Its behavior changes at roughly 60%, 20%, and 10% HP. During phase transitions, it leaps into the air and follows with a long-range breath attack, which serves as a clear cue.
How to Fight at the Start of the Battle
Four Main Attack Patterns
The Corrupted Ancient Dragon has four primary attack patterns at the start of the battle. Other attacks, such as Tail Slam, have limited range and often miss, so they are low priority.
Detect the Spin Attack by Its Roar
The full-body spin attack is telegraphed by a distinctive roar. Dodge it with a Just Dodge or by creating distance.
Move to Safety for AoE Attacks
When the Corrupted Ancient Dragon stands on its hind legs and roars loudly, attacks will rain down on random locations. Move out of the area of effect to avoid them.
Powerful Line AoE After Brief Flight
If the enemy briefly takes off and then lands, it signals a powerful AoE attack. The effect is linear, so move left or right to avoid it.
Normal Breath Is an Opening
The frontal breath attack leaves a large opening, making it a prime chance to counterattack. Move to its side and deal damage.
How to Fight at 60% HP Remaining
New Actions are Added
When its HP falls below 60%, new attack patterns are added. Some attacks are also enhanced, so proceed with caution.
It Also Starts Breathing Fire at Its Feet
A new variation is added to its breath attack, causing it to breathe fire at its feet. Attacking from the side is no longer completely safe, so remain alert.
When Airborne: Back Off, Dodge Left
While airborne, it uses various breath attacks, making close range dangerous. Move away immediately. For the landing charge, it always sweeps its tail to the right, so dodge left to avoid it.
Charge Attack is a Chance for a Stun
It gains a new charge attack, "Overload." If your Combat Power is sufficient, continue attacking to trigger a Stun. If your Ultimate is unavailable or your Burst Gauge is low, create distance and dodge.
How to Fight at 20% HP Remaining
Collapses on Landing After an AoE Attack
As its HP decreases, it may fail its landing and collapse. Use this opening to deal significant damage, as the next phase becomes more challenging.
In the Story, the Book of Stars Will Help You
In Main Story ACT 12, the Book of Stars assists during this phase. Move to the center and interact with it for support against the Corrupted Ancient Dragon.
How to Fight at 10% HP Remaining
When its HP falls below 10%, it enters the final phase. It will trigger a field-wide DoT attack, so defeat it before your HP is depleted.
Corrupted Ancient Dragon Combat Tips
Use Phase Transitions to Recover
During phase transitions, the enemy creates distance, giving you time to regroup. Use this window to heal or apply buffs. Its AoE attacks and tornadoes are predictable, so handle them calmly.
Use Tag or Ultimates to Evade
For hard-to-dodge attacks, use the invincibility frames from Tag or Ultimate Moves instead of relying on Dodge.
Jump + Dodge is Easier to Evade With
Instead of dodging, use a Jump + Dodge while moving to cover more distance with less Stamina. Vertical movement can also disrupt homing attacks, so take advantage of it.
Utilize Food and Potions
If you're struggling to clear it, use potions and food. Boost HP and defense for survivability, or increase attack to shorten the fight.
Prepare for Corrupted Ancient Dragon
Upgrade to Recommended Combat Power
When attempting high-difficulty dungeons or Boss Challenges, check the recommended Combat Power before starting. In time-limited stages, insufficient Combat Power makes it difficult to defeat the boss within the limit.
Character Progression Priority
Try Using Multiplayer
If solo play is difficult, try multiplayer. Team up with other players to tackle powerful enemies and earn rewards.
Register Potions to the Quick Slot
When facing powerful enemies or bosses, register healing potions to your Quick Slot beforehand. This allows for instant HP recovery during battle.
HP Recovery and Healer Heroes List
Related Articles
Quest Guides
Main Story Walkthrough Guide
Act 1
Act 2
Act 3
Act 4
Act 5
Act 6
Act 7
Act 8
Act 9
Act 10
Act 11
Act 12Boss Guides
 Albion Guide |  Banakro Guide |  Draco King Drake Guide |
 Red Demon Guide |  Corrupted Guardian Golem |  Gray Demon Guide |
 Twigo Boss Guide |  Molbog Guide |  Corrupted Warden Orgot Guide |
 Guila Boss Guide |  Corrupted Ancient Dragon |
