Leonas damage from masteries.
Leona is having an issue where, when a rune gives AD or AP damage, it gives her AP. Yes, I know she has AP scalings, but AP has never been useful on Leona, whereas AD has(since her Q is a AA reset). I imagine Leona isn't the only champ having problems where rune pages are giving them the wrong stats. But I hope this gets patched and each champ is individually assigned AD or AP, rather than just giving any champ that has a AP scaling, AP over AD.