Here is the full list of all 52 Jerez's Arena achievements.
Earned All Achievements
Claudia End
True End
Ellin completed her 20th Mercenary Commission
Lose All Battles
Ellin completed her 20th Prostitution Quest
Fed the birds with Claudia
Cleared Conqueror Mode.
Defeated Isekai Adventurer Lica in Conqueror Mode.
Defeated Glenn at the height of his power in Conqueror Mode.
Ellin End
Watched Ellin dance
Claudia completed her 20th Prostitution Quest
Saved Ellin at the Tavern
Bad End
Claudia completed her 30th Conditioning
Ellin completed her 30th Conditioning
"Technique" reached 200!
"Kinkiness" reached 200!
"Obedience" reached 200!
"Seduction" reached 200!
"Lewdness" reached 200!
Reach any Ending
Win Ellin's third battle
Accumulate 100000 G worth of wealth
Claudia completed her 20th Mercenary Commission
Win Claudia's third battle
Win Ellin's second battle
Ellin completed her 30th Training
"Agility" reached 200!
Completed Claudia's Oiran Request
"Dexterity" reached 200!
"Stamina" reached 200!
"Strength" reached 200!
Punished Ellin for stealing
"Willpower" reached 200!
Win Claudia's second battle
Stopped the Noble from bullying Claudia
Win Ellin's first battle
Claudia completed her 30th Training
Completed the Undercover Mansion Mission
Ellin completed her first Prostitution Quest
Ellin completed her first Mercenary Commission
Ellin completed her first Training
Ellin completed her first "training" Conditioning
Ellin joined the team!
Win Claudia's first battle
Completed the Bandit Mission
Claudia completed her first Mercenary Commission
Claudia completed her first Prostitution Quest
Claudia completed her first Conditioning
Claudia completed her first Training