First thing is of course to determine base body. Naturally it must be a hibiki type body but which of the onis to use? There are only 2 parts you need to change and that is (1) his front chest metal armor and (2) his face. The rest are exactly identical like all SIC onis.
CHANGE HIS BODY
There are a few ways to go about this:
a) Use a hibiki body and do not change any of his metal armor pieces
b) Use a different oni whose metal armor pieces resembles more of Kyoki's. One example is Danki
c) Use a hibiki body but alter his metal pieces
I chose option (c) coz i dont have a spare Danki and I just so happen to have a red hibiki (with 2 broken elbows) available.
For the chest part, what I did was I switched hibiki's right side metal chest armor to his left chest and vice versa. Simple. But thats not the end of it as when you do the switch you will find (1) the holes to attache the metal pieces doesnt work anymore and (2) the metal links that hung beneath his armpits are too long to fit the inverted metal chest pieces.
You will need to:
1) Cut off some parts of his chest piece to allow the inverted metal chest pieces to fit in. Drill holes at the positions where you need to fit in the inverted metal chest pieces. You will also need to probably cover some of the connection holes that is no longer useable with putty.
2) You will need to cut the metal links underneath his armpits shorter using a large pliers. I basically grab the metal links with my pliers and then push it against solid tarmac ground until it breaks ;p thats one way to go haha.
3) You may also wish to resculpt the central jewel piece to make it more prominent. You will need to poke a stub of putty on the centre of his chest. Then wait for it to dry. After it dries cut it into diamond shape with a blade (see pic below).
4) Once you did the above 2 steps, glue the inverted metal chest pieces and the links on the body. Let them dry.
You are now done with the body. As a added step, I actually add some putty between the inverted metal pieces and the links to make them more linked. I also add putties to the connection between the inverted metal pieces and the back metal pieces as they now doesnt fit properly together.
CHANGE HIS HEAD
The problem here is I didnt take enough photos of his head to let you see clearly what I did :( Basically I added 3 putty crooked lines along his face to resembles Kyoki's face. Back then I didnt know any other technique to sculpt putty except to use my fingers. I have to shape each lines after the prior one dried otherwise very hard to control the tiny putty pieces. I use my thumb and pointer and squish the putty to form jagged edgy lines. For the v shape on the line, I use toothpick to manipulate the putty. After they dried, I sand them a bit to make the edge more profound. See the photo above and below.
After that its a matter of repainting the whole thing. The broken elbows I used revoltech joints to repair them. I first sand everything to make the paint sticks. Then I paint a layer of silver and white over the whole body. I then paint a later of super metallic silver over it. Then the blue parts are gloss light blue and his underwear is a brown. Themetal pieces are gold metallic. Well thats it.
This is how he looks like before you do linings on him: You can actually stop at this stage if you want to.
Post lining see below (it took me 1 hour to do the linings!)