Bound By Flame
41 Achievements
Psycho killer
Kill 50 enemies with an axe
4.7%
How to unlock the Psycho killer achievement in Bound By Flame - Definitive Guide
All the kill trophies are fairly straight forward. You can use any means to damage a monster before it dies, all that matters is the weapon you kill it with. You won't be able to max out both the Dagger and Warrior skill trees within the same run so try varying the weapon types you're using, if you don't want to spend a lot of time grinding out kills.
Axes, swords and warhammers all belong to the Warrior skill tree. Daggers belong to the Ranger skill tree. You don't need to align with one class or the other to use any of the weapons, but it is easier with more skill points. For this reason I recommend saving up skill points in Act I and then making a save. If you can obtain an axe, warhammer and a sword from Assael then I recommend doing so and grinding out these kills in Act I, reloading the same and spending your points elsewhere. You can sleep in your bed at camp in Act I and Act II to respawn enemies and farm kills. Kills are only calculated on a single save. You can not combine progress across multiple saves.
If you can kill with the warrior weapons without spending skill points, then 150 warrior weapon kills early on can give pretty good starting experience as well.