My Score Farming Method

[NanashiBQ]

In post-game, you can buy special Sigils from Liselotte that make farming Scores really fast and easy. By combining a purple Sigil and a Master Egg or Million Egg Sigil, you can do a boss fight Grimoire with an S Dungeon Rank. If you get the white/gold reward chest, you'll earn 8 Scores per run. Note that you need to earn the first reward from the purple Sigil before you can earn the Scores.

Here is the list of purple Sigils you can buy from Liselotte that drop and reward Scores...

Hellfire Spear

• Boss: Trishula
  
• Score Drop: Earth
  
• Score Reward: Shining

Frozen Halberd

• Boss: Gae Bolg
  
• Score Drop: Sea
  
• Score Reward: Sea

Thunderous Javelin

• Boss: Gungnir
  
• Score Drop: Sky
  
• Score Reward: Earth

Aquatic Sword

• Boss: Caliburn
  
• Score Drop: Shining
  
• Score Reward: Sky

Demonic Blade

• Boss: Dainsleif
  
• Score Drop: Dark
  
• Score Reward: Dark

Dragonshift

• Boss: Dragonshift Zest
  
• Score Drop: Dark
  
• Score Reward: Dark

Magician's Eye

• Boss: Ette & Joachim
  
• Score Drop: Dark & Sea
  
• Score Reward: Dark

Imperial Ninja

• Boss: Excella & Beatrice
  
• Score Drop: Earth & Sky
  
• Score Reward: Dark

Berserker Blade

• Boss: Jinas & Zest
  
• Score Drop: Shining & Earth
  
• Score Reward: Shining

Beowulf's Revenge

• Boss: Georg
  
• Score Drop: Dark
  
• Score Reward: Dark

On top of earning a lot of Scores, you'll also gain a ton of EXP and Gold. Use the Master Egg for EXP and the Million Egg for Gold.

I know some of the purple Sigils unlock as you progress in the game, but the Master Egg and Million Egg Sigils are unlocked at post-game.