Board Thread:Questions and Answers/@comment-24022762-20150713075119/@comment-26297531-20150713075925

the vocaloids (Luka, Miku, Rin, Len, Meiko, can't rmb what's the guy's name) are 1.. the soul bound saga units (Tridon, Ultor, Andaria, Hadaron, Aurelia, Zedus) are another.. i do not know of any older crossovers..