Here is the full list of all 14 Battle for Blood - there are Epic battles within 30 seconds! achievements.
Clear stage 60
Unlock Royal Knights
Clear stage 40
Unlock Wizard
Clear stage 25
Unlock Feudal Knights
Unlock Royal Guards
Unlock Armoured Swordsmen
Unlock Warlock
Clear stage 1
Clear stage 10
Unlock Sergeant Swordsmen
Unlock Archers
Unlock Eagle Warrior