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