I Didn't get even near 100 hits, but I still got the item for it. For me, ragnarok command didn't even appear, and I pressed triangle. and D&G was there, but they didn't attack pink agaricus? Was I just lucky, maybe, lol.
When you Target it press R2 and you will target his face which will allow Ragnarok to appear. Also cast Areoga that'll get you a bunch.