Thank you for the reply Vort, my first time using the guide creation on here so it is a bit lackluster I know. I'll try to update it if I can ever get a day off work!! and certainly take your comments into consideration. I don't have 2000 wins, so in truth I don't play around much with marks, I tried to verbally play that off with versatility remarks, haha. Your input is most appreciated.

Your guide could use some visual assistance, but I like what i'm seeing so far! I use a very similar build for support leona, with great success. A few suggestions, however.

Spells: Consider taking Heal, as it allows you to pull off kills and escapes you would not have been able to otherwise. You can also bait the opponents to dive you with it, and then once they do, stun them and pop heal.

Skill order: Is lovely.

Runes: Your marks and quints bug me a little bit. I honestly don't think leona gets much out of spell vamp, and she doesn't need the small amounts of extra health provided by the marks. In my opinion, armor pen marks will provide you with the strongest foothold in lane, as they'll boost your damage a strong bit in the early game. Late game, you're a CC tank, so that doesn't even matter. As for qints, there are a few approaches. You could go the utility rout, and grab gold per 10 quints or movement speed (as leona is crazy slow), you could throw health or resistances in here to be even tankier in the early game, or you could go with flat AD to further boost your early game damage output. Or one further note, if you decide to start Faerie Charm and wards, you could take health regen quints to buffer your health regen before you have your Philosopher's Stone.

Items: I really like your items save a few select things. First of all, Will of the Ancients doesn't provide you with anything substantial, save AP, and as a late game tank, there are better ways of picking up a little extra AP if desired. Also, as a support, your gold income will be rather low. You might consider picking up a second gold per 10 item to assist in this manner. A Heart of Gold should do the trick. I personally go for an earlier Sheen, as it helps with your damage output and mana, quite substantially, and then I don't touch my trinity force until the very end of the build. I also prefer getting my Aegis of the Legion before my Frozen Heart, as the item is, simply put, very strong. Sometimes, I even build my Shurelya's Battlesong before my Frozen Heart. It really depends more on when team fights start breaking out. It's an incredibly good team initiate and follow up item. In place of Will of the Ancients, I prefer either Warmog's Armor against a single AP team, or an Abyssal Mask against multiple AP champions.

Once more, great guide, and I hope you can pull something useful out of my text wall!