Here is the full list of all 55 Wulverblade achievements.
Beat the game in any mode as Brennus
Transformed into the Wulver for the first time
Kill 1000 enemies
Defeat the praefectus without losing a life
Find 25 history unlocks
Kill 500 enemies
Destroyed 100 amount of Destructables
Find 10 history unlocks
Kill 250 enemies
Build up a 100 hit streak
Find one secret area
Kill 100 enemies
Build up a 25 hit streak
Defeat the level 1 boss without losing a life
Defeat the level 2 bosses without losing a life
Defeat Arthal without losing a life
Defeat Bronwen without losing a life
Defeat the level 6 boss without losing a life
Defeat the Primus Pilus without losing a life
Kill 5000 enemies
Reach wave 10 in an arena
Reach wave 20 in an arena
Reach wave 30 in an arena
Build up a 300 hit streak
Hit 100 enemies with throwing knives
Hit 100 enemies with dismembered pieces
Hit 5 enemies with one ground slam or heavy weapon jump slam
Kill 10 enemies during a single rage
Kill 3 enemies with fire within 10 seconds
Complete arcade mode of the campaign
Earn rank 3 on all campaign levels
Complete Stage 1 in Arcade mode
Complete Stage 2 in Arcade mode
Complete Stage 3 in Arcade mode
Complete Stage 4 in Arcade mode
Complete Stage 5 in Arcade mode
Complete Stage 6 in Arcade mode
Complete Stage 7 in Arcade mode
Hit 5 enemies at once with a single exploding barrel
Complete all levels under par time
Beat the game in any mode as Caradoc
Beat the game in any mode as Guinevere
Find eight secret areas in one session
Find the Golden Axe
Have a hot roasted turkey or ham when your health is already full
Spared the sleeping Roman in Fort Bremenium
Finish off 50 enemies with executions
Finish off 250 enemies with executions
Impale 25 enemies on spikes
Impale 100 enemies on spikes
Impale 1000 enemies on spikes
Counter 50 times
Counter 100 times
Counter 500 times
Destroyed 1000 amount of Destructables