@Zerahtai They are Unlit, but some champions like xayah and rakan has specific specular shaders also detail map. Mostly they only use diffuse map, all the other details such as reflections and light fx are faked on the diffuse texture.
League characters are unlit in-game. Any lighting information (gradient map, AO, point light, fake emissive...) is baked/painted in the diffuse texture.