Max Eclipse at level 9, way more effective. I think the one Greater Quintessence of Gold and Greater Quintessence of Ability Power can be replaced because gold generation Runes aren't necessary after the changes to gold income and Quintessences like Greater Quintessence of Health seem to be niche choices. For Leona I suggest you running a more defense oriented Mastery setup like 0/21/9 or 0/13/17 because I find myself always easily beating (bullying out of lane early) Leona's with low resistances with nearly any ranged support. If you still prefer your Mastery setup your should really select Wanderer at least.

I have to ask... It'd be nice to add a full example build for ppl in a hurry
Overall I'd say it's a very good guide, but the guide part is waaaaaaay too short, you lack information