Hello all!
This is my first build but I hope it will be helpfull for some players who want to start playing leona or increase their skill with her. Of course, I am not best leona player on the world and all your negative and possitive comments are welcome!

Leona is generally one of best supports in this game, in my personal opinion she is the best support out of all.
This is thanks to various things, mostly thanks to her stuns, slows, armor, magic resistance, tankiness and for sure she is sexy!

I have chosen Leona because I am playing her a long time, I love her and she can REALLY counter every one other support in this game for now! (Of course, depends on player skill and gameplay, and a lot on your adc too)

As I said, this is build for AGGRESSIVE LEONA, so all items will be used to engage enemies, deal significant damage and engage hard in early/mid/late game all of enemy team not only on your lane!

My item build is composed of items which give you nice HP, nice Armor and at least some damage burst.

The most important items are Sunfire Cape and Righteous Glory.
Sunfire is very good damage burst for you at start, this is my first item all time - Very good HP, armor and damage burst in one item!

Righteous Glory is my second choice, because it will give you and your allies nice movement speed bonus and on the end of duration very good slow (Or you can use this slow by reactivating item)

All other items are used to burst your HP and Armor. Some items are very usefull only in some situations, depends on enemy champions pick.

This is my favourite abilities build.
I am starting with E, because it is very good for early engage, very good for help your jungler at start and it can stop enemy champion too.

In this aggressive build we will max our shield spell, because it is dealing most damage out of all spells, it give you armor and magic resist when you use it and it is pretty nice spell!

Our next spell which will be maxed is our Spear, because we need to short her cooldown to minimum for more negages and better damage.

Last spell we will max is our stun. We will just need to short it´s cooldown, because it is very usefull spell in all parts of game if you use it good.

Ability usage:
Early game:
W > E > Q
If you are level 6, you can go:
R > W > E > Q

The next usage depends on cooldowns, you will need to learn your coodlowns and watch them all the time because it is the most important thing.

I am using classic masteries for support, so you can get golds faster and you have some good advantages for you and your adc 0/9/21

I am using runes for HP, Armor and Magic resist because we will be main initiator most times in teamfights and on the lane!

Leona is very good support with a lot of stuns so she is really one of the best supports in this game, maybe the best (in my opinion she is the best!).
She can counter like 90% of champions thanks to her CC and good movement and this is reason why you shall try her!

She is one of best tanks, one of best CC champions and sexy girl!

Thanks for wiewing my guide and I will welcome all your comments, either possitive or neggative.

Have a nice day and enjoy!