Actually unpopular opinion: Leona is a jungler, not a support.
She has A tier clear speed, clears within a fraction of a second of Nocturnes clear. *Not godtier clear speed, that is limited to champions that can dash over walls, and save travel time.
She has strong ganks. She has strong build paths. She has strong duel power, with a few exceptions that give her trouble. Udyr will beat yo ass in the early game if you walk into him, whereas a Leesin, or a Xin cant beat you up.
Leona in the bot lane, is just outright hardcountered by nearly every bot lane matchup that there is. The things shes strong against, are so rarely played that she hardly ever is a optimal pick, and you are virtually always better off picking Alistar. Zenith blade is denied by every support in the game that isn't Sona. to make matters worse, Zenith Blade is denied by half the ADC's as well. That insanely slow, predictable, telegraphed missle of a engage is too easy to counterplay in the bot lane. Theres no reason to not pick Alistar and point and click your Headbutt, its faster, impossible to miss, and all around more functional in a bot lane environment. Leona can actually land Zenith Blades if she has Mobis+Deadmans+Relentless Hunter, sitting in a support slot doesn't really give her the opportunity to build a deadmans tho. Jungling does, and it really makes her shine.
