Mortal Reminder Active and cooldown

Riot. currently you have Warwick, Mundo, Vladimir, Swain, Aatrox, Fiora, and Olaf that I can think of off the top of my head who heavily rely on healing in their kits. While i recognize that sometimes their self regeneration can get out of hand. Would you please consider changing Mortal reminder to an active? or even a targetted ability?

For champions like those listed above It doesn't really create much counterplay for them, and shuts them down pretty hard. Some more so than others. As Warwick when someone gets a mortal reminder I suddenly know that none of my healing will be enough to help me in a teamfight, and I can simply no longer duel that person unless my raw damage output is enough to get through them.