If not select the shader under XSI explorer, and refresh Render Tree window. You can see the render tree of current shader. Not Toony I know, but it's a simple thing how we can achieve Toon Look in XSI

So this is how the Robot look with Lambert Shader. You can do this with ambient lighting, but I prefer this way. Also Incandense is very important for keeping the material in dark scense lighter. The reason why I use Lambert Shader with Toon Shader, and not just Toon Shader itself, is that I can modify Color, Transparency, Reflection and Incandescene there. I love Lambert Shader, and in fact I don't need specularity now, because I will apply this with Toon Paint and Host Shader. First you need is apply the shader to the mesh. Let's see step by step how I gave toon shader to this Robot. Make it simple and attractive to the eyes. It's wrong to think that Toons must be colorful. Find colors what will make the character stand out and visible. The colors need to be bright, but if your characters are too colored, use simplier enviroment for them. Even the dark blues of night would look better, believe me.

Even though it's that easy you do need to keep in mind a few rules. It's easy to get a Toon look just in minutes. It has great animation tools for Toon animation, and also great shaders.

Iclone toon shader