User blog comment:Seieireppa/~40-second Crimson Orochi kills/@comment-29946617-20160911213034/@comment-1419424-20160911233312

Glacier Crocjaw is the hammer, Reinforced Blast is the gun (although that requires killing this in the first place, so substitute the Ci Cerca instead), Makuta Danti is the shield, Bennu is the CU (although this is irrelevant and you should use Assassin instead if you don't have Hidden Attack), and Goddess of War's Gun is the second upgrade part, and the only relevant one.

And as for the bullets, after further testing I've found a far simpler bullet that can do the job:

1: SS Deco-laser: Straight/long

2: SS Deco-laser: Straight/short, up 90°, when 1 fades

3: M Orb: Stop/short, down 90°, when 2 fades

4: SS Deco-laser: Straight/long, down 90°, with 3

5: LL Bomb, when 4 hits

There's another bullet for when it gets close, but for that, you just copy this bullet and remove the first module. This bullet is easier than the other one because all you have to do is aim down the sight and pull the trigger. I'll update this post with new screenshots and correct pledge information momentarily.