New Twisted Fate passive idea (his current one makes no sense)

I think that twisted fates passive makes absolutely no sense on him, so here's a more fitting idea.

Passive: Lucky Coin

After killing a unit, Twisted fate flips a coin. If it lands on heads, he regenerates health equal to 10% of the killing blow damage. If it lands on tails, he lowers all his cooldowns by 1 second.

Just an idea. If you don't understand the passive, then read further and I'll break it down.

Heads: Let's say he deals 40 damage with an auto attack to kill the minion. He would heal 4 health. If he hits them with a Q that kills them and deals 120 damage, he heals 12 health. Basically, he heals 10% of damage dealt to an enemy if he kills them with the damage.

Tails: Every single skill Cooldown, including his ultimate, will be lowered by 1 second.