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