This is great, I'm actually going to try it out for 2-3 bot matches and then go to normals and see how much fun I have.

As this guide is under "fun," it is supposed to be fun. The entire purpose of it is just to build things that have synergy with each other.
The entire point is just to mess around, if I were to try with Singed I would do something entirely different, worry not.

Hey!

I found some issues on this guide:

1. I really don't understand why you picked Manamune on Singed, he isn't a kinda of champion that it's using abilities whole the time like Karthus, Manamune on Singed it's a really bad item tho.

2. Atma's Impaler? Buying this item only will be a waste of money and time, Singed isn't a source of meele damage in the figths, I prefer to buy Force of Nature.

3. You are wasting alot of IP on Knowledge's runes, you don't need that quantity of mana, i know that the Singed's passive work with his mana, but this mana is given to you by his item non his runes. I prefer use Move Speed quints or something else.