The "Next champion at" fame level indicated in the mouseover over your fame level gives an incorrect fame amount if your Fame drops below what was needed for your previous champion due to consuming fame through, say, building Henchmen. I noticed this after getting my 50 fame-level champion, then building Henchmen which consume 20 fame, then the "Next champion at" indicated I would get a new champion at 50 fame (which I had already surpassed then fallen below). However, upon re-surpassing 50 Fame, I did not receive another Champion (and the "Next champion at" then correctly displayed my next champion would come at 100 fame).