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