1) Ihatov is a fictive place where Miyazawa Kenji’s (a Japanese author) stories and poems are set. It’s a very mysterious one. If you want to read up more info about it, take a look at this article!
2) The “untranslated” parts are written in the language of youkai, thus “we humans cannot understand it” (comment by Stack).
3) Mayohiga is a place full of cats. Its name would translate to “Stray House”. As I commented on “Destiny ~ Spring has come at last”: Blame Chen!
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.