So many times I'll often search something on Kagi, get no results, and tag on the "!g" at the end to see what would happen. Of course, I get a ton of results that have nothing to do with what I was searching for. I love Kagi.
Kagi uses results from almost every search engine in the world plus its own results. If you can not find something on Kagi, it is likely you will not be able to find it anywhere.