Introducing 2 formations that reaches score limit. One with Refithea and other without her.

Point 1：Dagdarone will not take damage while it's in invincible mode. Only after it takes 18 normal attacks, it will take damage. So you have to use mercs with multi-attacks. With my setup, Aie is the one who blows 18th attack.

Point 2：Dagdarone will counter attack when being attacked while it is in invincible mode. You have to use supporter(s) to protect mercs. If you have Refithea, she's all you need for this task.

Point 3：Once you break invincible mode, not only Dagdarone take damage, but also debuff becomes effective too. Stack up strong Inc DMG boosts. Please see here for recommended mercs with incoming DMG boost skill here. The last striker is the PvE destroyer Gunther.

Point 4：This boss has a unique mechanic that every time it get attacked, it becomes Dagdarone's turn. So if in one round it get attacked 5 times, it also has 5 turns. This mechanic really does affects supporter's buff duration. Buff duration from old supporters are typically 10 to 12 turns which maybe too short. Make sure your attackes' buffs are not expired.

Point 5：The position of Lyudmila, and Catherine is actually calculated. They will fully heal on 2R after Christina's attack because of their high DEF from Helga's buff.

Point 6：You might be wondering why using Helga who doesn't have any incoming DMG boost or her buff duration is too short. The reason is Refithea, and Isabel can give stronger buff to the attackers while their support is still increased by Helga's buff.

☆☆☆ With Refithea ☆☆☆

1. ★6 Refithea+15
2. ★6 Christina+15 (Multi-attack 5 x 2)
3. ★6 Ingrid+10 (Multi-attack 3. Need to die after attack)
4. ★6 Ceres+15
5. ★6 Aie+10 (Incoming DMG boost +300%)
6. ★6 Orienne+10 (Incoming DMG boost +125%)
7. ★6 Denarisa+10 (Incoming DMG boost +125%)
8. ★6 Zarka+10 (Incoming DMG boost +145%)
9. ★6 Catherine+15 (Incoming DMG boost +120%)
10. ★6 Lyudmila+15 (Incoming DMG boost +300%)
11. ★6 Gunther+14 (Incoming DMG boost +95%)
12. ★6 Helga+15 (Die after Gunther's attack. Increase supporter's support.)

☆☆☆ Without Refithea ☆☆☆

1. ★6 Helga+15 (Die after Lyudmila's attack. Increase supporter's support.)
2. ★6 Seol Ah+15
3. ★6 Galania+15
4. ★6 Christina+15 (Multi-attack 5 x 2)
5. ★6 Dr. Morgan+10 (Multi-attack 3. Need to die after attack)
6. ★6 Aie+10 (Incoming DMG boost +300%)
7. ★6 Orienne+10 (Incoming DMG boost +125%)
8. ★6 Denarisa+10 (Incoming DMG boost +125%)
9. ★6 Lyudmila+15 (Incoming DMG boost +300%)
10. ★6 Catherine+15 (Incoming DMG boost +120%)
11. ★6 Zarka+10 (Incoming DMG boost +145%)
12. ★6 Gunther+14 (Incoming DMG boost +95%)