Leona is a great support characterized by her amazing CC and insane tankiness. She is great at both engaging and peeling by being able to lockdown multiple targets with her 3 CC abilities. Her basic combo is to activate W to get in close without taking much damage, E the adc, and stun them with Q. Try to have your adc AA in between your abilities because Tthis will proc your passive and deal a lot of damage if done correctly. AA Q AA can quickly kill enemy wards immediately after being placed. Use your ult to stun and slow fleeing targets from range, engage, or use for AOE CC in teamfights.

Pros:
- AMAZING CC
- Lots of tankiness
- Great early game combo, can earn adc fist blood easily
- Allows for great burst with passive if coordinating with adc
- Can do well in late game because of AOE CC Ult for teamfights
- Able to get to the backline easily in teamfights because her E goes to the last target hit
- Can lock down a singular target for years

Cons:
- Early game mana problems, can use full combo twice in a short period of time and then very low
- If she falls behind early, she wont have enough tankiness to be able to engage late game
- If you miss an E, you will have also wasted a W if you activated it before engaging
- Not as useful level 1 as someone like blitz because she needs both E and Q to engage, and W is also useful for engages
- Doesn't have any ally buffs, heals, or shields, so she is not the best at disengaging/sustaining your adc

Early game:
- Use relic shield stacks on the cannon minion and remember it gives health to your adc, so use them when your adc is getting low
- Bully the enemy off their CS by moving up aggressively
- If your adc is doing well in lane, you can roam to mid to get an early kill using your CC angage
- You can tank dragon very well, so early dragons are easy
Mid Game:
- Go ward crazy with sightstone and pink ward Dragon and Baron
- Use upgraded sweeper to clear a lot of wards in a shot period of time using your AA Q AA combo
- If your adc starts chunking with their first items, engage hard on squishies earning easy kills
- Use ult into W E Q combo to get some long range engages the enemy wont expect
- Ult is great disengage, and also great in teamfights
Late Game:
- Tank Barons and Dragons
- WARD MORE
- Use your Q to stun super minions to delay sieges and W to help you tank their agro
- Tank turrets to help siege

Works Well With: (IMO, works best with Vayne)
Ashe- Double CC, pretty much impossible to run away from
Draven- Allows draven to have a lot less pressure catching axes when enemies are stunned
Graves- Graves needs to get in close for his abilities, and stunning them allows him to get in very close; can also peel for himself using E
Jinx- Relives a lot of pressure from Jinx early game with good CC, allowing her to become a beast late game
Kalista- Both great at engaging, allows Kalista to get maximum rend stacks into her opponents when they are stunned
Sivir- If sivir can start chunking with AA she can easily burst them down with her Q, W, and AA's while stunned; also has great engage/peel with ult
Twitch- Leona allows twitch to get max poison stacks on enemies
Vayne- Allows vayne to stack W as many times as possible; can peel for self with tumble, and can also line up condemn easier when opponent is CC'ed- Probably the best combo with Leona