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