The alpha channel of SpiderTex3 acts like a texture switcher ingame and switches it to SpiderEye, which acts like a matcap. a material setup screenshot for Blender users is included.
Also if the cape is fully red, enable back-face culling.

Models, Textures & Material Settings ripped with CTR Studio

Taranza ripped from Kirby: Triple Deluxe.
First ripped by Charles29, when it was pending the notes admitted to modifying the two textures mentioned above and merging them.
Then properly ripped by Somwonere without the texture edit, credit not needed but appreciated.