Mnh... As a big fan of the Dark Warrior(I mean a more than 30 years old fantasy archtype, not WAR clone), I do like the idea of to add Death Magic to the Dark Knight, but I am less confident in that some of those action affects feel like a little even more WAR clone, and also not certain about if the "DarkSide can not be active while death is active" part is a good idea...
Those two concerns aside, I do sort of like the core idea that this set of actions has for them.