And i still don-t know what this "ROKKON SHOJO" is. I did goggle it, but it's not like the replies i found explain it's use in the anime. Oh well. For now i love the music so i'm cool. Thanks for the upload by the way.
It translate into "purification of the six roots of perception" https://haikugirl.me/2014/12/14/word-of-the-week-rokkonshojo/ look here for a bit and gives a bit of an answer
I think Rokkon whatever is an actual battle cry from the era the show spoofs. As others have said, it's a mantra for focus of some sort, but apparently the details are very complicated.