Currently on PC, patch 6.3.2, whenever I select the armored titan skin for Oni in the shop, the blood fury enraged model variant does not render the hardened portions correctly. I cannot attest as to whether or not it renders correctly in matches. I have not seen this skin up close in the current patch nor do I own the skin. I presume, however, that if the models are the same in the store as they are in-game, then it most likely is occurring in-game.

Step 1: Open the game and enter the in-game shop

Step 2: Select character tab and select Oni

Step 3: Select the Armored Titan skin

Step 4: Wait for the blood fury animation to play, which reveals that the hardened portion of the skin are not rendering correctly

I am able to replicate this each time I open the game.

Here's an image of what the skin used to look like when viewing the skin during blood fury on release:

And here is the skin in the current patch, 6.3.2: