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