This is an off meta build very near and dear to me. It will almost certainly get you reported and flamed even if you're *****tomping lane but man is it fun to slap someone and gain back a quarter of your health.

It works because
1. Your Q is an auto reset so you can lifesteal faster
2. Most league sweaties have no idea what grievous wounds is
3. Enemy laners will see your build and get cocky enough to towerdive you, forgetting that you're still Leona

You're a bruiser/assassin similar to a crippled Irelia; just jump in, stun as many enemies as possible, then beat the daylights out of them while sustaining off your lifesteal (so you don't get instantly deleted).

I'll definitely expand this guide in the future, more testing needs to be done with the new item shop.