Those are two drastically different artstyles. Neither of them really are engine shader stuff, just someone drawing good textures in Photoshop.

Paper Mario is all hand-authored baked vertex colors and very simple textures. Artists spent a lot of time in Maya hand-tweaking each vertex individually, e.g. see my viewer here https://noclip.website/#ttyd/jin_00

Borderlands has some basic engine technology with outlines -- running a basic Sobel on the depth buffer to find depth discontinuities and drawing lines there, but most interior lines are on the texture itself. Lighting is also modified with a ramp -- the "raw" incoming radiance from lighting is thrown into an artist-authored lookup table and tweaked before being thrown to the shader. Normal maps are seldom used.