Build tanky early get fast Randuin's Omen and Aegnis Of Legion or Mikael's Crucible good vs mixed dmg teams then go that way of your defencive stats so u can tank more and more and live long enough to peel your adc fully

u can go max hp quints yellows or flat its what u prefer i like blue scaling CDR because its ****ing op with Locket and Face of the mountain u got 40 at 18 lvl mixed armor and scaling armor yellow are pretty good double penetration red gives u **** ton of dmg i reccomend it or just armor pens leona got huge base ad

standard support masteries but u can go more tanky version with 4:21:5 with 5% cdr in masteries

u need to go tanky omen is pretty good vs vayne and overall ADC/Marksman u can tank more and do your **** remember if u aren't doing pretty well dont go righteous glory couse u need ****ing armor and resists thornmail vs Auto-attack focused team with tryndamere and vayne aatrox etc. aegnis is great vs strong MAgic dmg poke fromm their over fed modlaner and helps your adc to get some of those resists

Ignite is great 2 but remember vs vayne or smt with high DMG go exhaust couse it reduces dmg ignite is must have vs soraka or sona SMT like that

Pros:
-Great Eangage with ulti and combo
-Great CC Lock
-High DMG early
-Passive op great dmg

Cons:
-Pretty weak peel
-u can or eangage or peel not both at the same time
- Ulti is easy to miss and juked Because of cast time

1. Graves
With his great over all kit and ****ed tons of dmg at lvl 6 he is perfect Graves got tons of burst and with leona u will overwhelm your opponents with your combo with him great burst and over all best pick with leona
2.Sivir
great adc with leona u get good buff with her movement speed buff so u can just run to their adc and stun them she got spell shield so she can peel herself with her movement speed buff and cc block
3.Ezreal
He go one of best poke in game good mobility and tons of dmg with ulti u can easly burst their adc with your combos
4.Cait
Caitlyn is one of easiest adc in game great poke with AA and high dmg Ulti u can easly kill one of them on bot like by bursting them with your combo and cait Q and W great cc lock combo wombo and just DELETE THEIR ****ING ADC AND TYPE IN ALL CHAT SHE ****ING EXPLODED !!!! then just kill support with cc and cait dmg ulti and easy double kill bot
5.Corki
High dmg early he got tons of mixed dmg like you and great mobility good poke post 6 LvL and nice early dmg with q
0.Vayne
just stun support or adc near wall and its free frag hard early with weak vayne good and op **** with good Vayne