Sightstone/trinket Upgrade suggestion

So a few times Eve has rly been a pain in my games. she gets perma stealth and buying pinks early is really annoying. same with rengar once he hits 6, no warnings unless u have a pink in the right spot and it doesnt get cleared in time. From this frustration I thought, why not make a trap item? Not necesarily one that hurts the enemy, but one that alerts the player, specifically for stealth. The idea was that Sightstone or the trinket could be upgrade into an item that will spawn two wards with a tripwire between them. Activating the trap would cause a ping and the owner of the item would be alerted through a sound as well. This trap doesnt have to reveal stealth, but would slow the champion for 0.5 seconds. It could be used to counter stealth approaches that are undetectable at early levels where pink wards arent an option and would be cleared immediately. The main problem with Eve for the enemy mid is that she can gank at any time and in lower elo it makes her really unfun to play against.