Here is the full list of all 21 Burial Stone achievements.
Learned Fierce Slash talent
Learned Fierce Hack talent
Learned Fierce Club talent
Learned Cross Slash talent
Learned Blood Cleave talent
Learned Blunt Stun talent
Learned Fire Bolt spell
Learned Radiant Light spell
Learned Magic Shield spell
Learned Chain Lightning spell
Learned Piercing Light spell
Learned Regain Health spell
Started in floor 1
Reached floor 2
Reached floor 3
Reached floor 4
Reached floor 5
Bought an item from the shop keeper
You entered the final boss hall
You defeated the final boss
You entered the shrine