I'm assuming because of multiple amounts of Kunai, it is used in conjunction with clones and each clone will use Rasengan from different spots and bombard an enemy. However, this is just an assumption.
Shiki means Spirit and there's obviously something to do with Rasengan plus the Hirishin no Jutsu from at-least 6 direction is involved hence the Kage Bunshin!
What we know from how he was trying to use it is: 1. It required multiple kunai, 2. The original Minato was necessary, and 3. The opponent needed to be immobile. I think he was going to scatter the kunai, creates several shadow clones, and transport different parts of the Juubi to each kunai, ripping him to pieces.
its a dance so it should be multiple rasengans. i dont get the howl ring flash bit. i get the flash means instant.
i think the jutsu's name is: howling spiral flash ring dance technique.