LeBlanc Passive Lockout Timer

There should be an indicator to know how long again until you can apply the passive. Call me ignorant but I'm not sure if this already exists against champions but I know for sure this doesn't work against large monsters/epic monsters and I think it would be helpful if there were such a thing. I need around 2 - 3 rotations of spells to kill buffs and knowing when to use my spells (to proc. the passive instead of just spamming and smashing my keyboard) would really help.