I just realized while rereading this, but I felt that "qbara qbara"/kuwabara kuwabara sounded kinda familiar, before, and now I remember that it's because it reminds me of the korean phrase "Baraya, baraya, agabaraya" that I learned from SSS-class S**cide Hunter.
I know that they're not really related to eachother, since kuwabara is superstitious way to ward off lightning, and baraya is a kind of prayer with Indian origin, but I think that's why it sounded kinda familiar to me.