Here is the full list of all 10 Slash or Die achievements.
Collected a total of 10000 souls
Completed game playing for Mage
Completed game playing for Berserk
Your 100th death
Completed game playing for Warrior
Character unlocked: Mage
Collected a total of 1000 souls
Character unlocked: Berserk
Your 10th death
Collected a total of 100 souls