Here is the full list of all 10 Mortal box achievements.
Watch a servant die
Lose the title after defending it 10 or more times
Complete a game of 3 players
Replace every record with one of your own
Return from the 7th face
Take less than 2 minutes to win a game of 1 player
Play a game of 10 minutes or more
In a moment, every player should have 6 points
Win a round having your screen black
Use a secret code