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