Champion that detects Stealth

I think it would be nice to have a champion that can see stealth champions or stealth traps like Teemo Shrooms if he is within xx units. That way if an enemy team is using Rengar, Twitch, Teemo and other stealth champs, players don't get 1v4 ambushed. It also makes stealth comps have to play more cautiously because they don't have the ambush element to give them an advantage.

Making a kit for this type of champion would be interesting because you can't make a kassadin kit designed to completely counter stealth champions the way kassadin counters AP and magic damage champions. Perhaps just give this champion a passive that detects stealth then build the other 4 abilities from that. or maybe turn the passive into an ability with a low - medium cooldown that perhaps stuns stealth champions in the area if they are stealth.