Stack seemed pretty proud about this song on her Twitter page, and I can understand well why she did! She’s been studying English for some time now and I don’t really spot mistakes anymore. Good job!
‘Deathfrantic’ per se appears not to be an existing word, but a combination that literally means ‘a frantic death’.
1) “Kirisutgomen” literally means “the privilege of a samurai to kill commoners for perceived affronts”. Thus I translated the line as “The circle of karma is under my control” since when you control the samsara, it simply means you kill people before it’s their time to die (=when you, the samurai, think they should die)
2) “Rakshasa” are man-eating demons in Hinduism and Buddhism.
3) “Shurakura” is a state in which ones heart is in complete rage and/or jealousy and the person goes crazy. “Uzumaku” can be translated to “jumble together (emotions etc.)” but I figured that it’s sufficient to keep it short like this.
4) “Mu ni kaeru” means something like “return to point zero”, so the state of a person before they were born. Since Youmu wants to return all transient realities to that point, I chose “ground zero”, which is the state the universe was in before it came into existence. This might be a bit too extreme, but since Youmu’s heart is completely eaten by rage, that’s probably really what she strives for.