Here is the full list of all 29 Scarlet Maiden achievements.
Slay 200 enemies in one run
Completer the quest ‘It’s a Strap’
Earned after 10th run
Complete the quest ‘Green Delight’
Defeat Queen Lily
Level Faelina to level 5
Complete the quest ‘Magic Flute’
Complete the quest ‘Masquerade’
Level up to level 50
Level Roman to level 5
Defeat the Grand Archivist
Gain 100000 sin total
Slay 100 enemies in one run
Find 50 items in one run
Complete the quest ‘Steamy Contraptions’
Level Bruce to level 5
Level up to level 10
Gain 15000 sin in one run
Defeat the Earth Mother
Find 20 items in one run