The level inside the bracket means the possible drop from corresponding Registlet dungeon level.

Rarity may be inaccurate. It is divided into:

• Common: 60% Chance
• Uncommon: 25% Chance
• Rare: 10% Chance
• Super Rare: 4.25% Chance
• Epic: 0.65% Chance
• Legendary: 0.1% Chance

Source:

• this Google Docs
• Toram Xensei Discord server
• coryn.club
• Phantom's Library Discord server