Datamined changes from current PBE release. Be aware that these changes are tentative and they might be changed or even reverted prior to the live patch.
Datamining only captures numerical changes. It doesn't capture changes to mechanics and bugfixes that may also significantly affect balance.
Due to the nature of how the datamining works it may also includes some of the changes that are already added to the live version in the most recent patch.
Updated: Jul 21 1PM

Briar

Twisted Fate
Draw a card with a value between 1 and 9 by Lucky chance, then throw it at the target. Based on the card drawn, deal between 205/305/460 (
) and 410/610/920 (
) magic damage. Overkill damage bounces to the nearest enemy. 3-Star Bonus: If a 9 is thrown, generate 1 gold.Lucky: Check twice and take the better outcome.
Max Damage: 610 (
) [410/610/920]
Draw a card with a value between 1 and 9 by Lucky chance, then throw it at the target. Based on the card drawn, deal between 205/305/460 (
) and 450/675/1015 (
) magic damage. Overkill damage bounces to the nearest enemy. 3-Star Bonus: If a 9 is thrown, generate 1 gold.Lucky: Check twice and take the better outcome.
Max Damage: 675 (
) [450/675/1015]

Akali
N.O.V.A. Damage: 22 (
) [15/22/28]
N.O.V.A. Damage: 18 (
) [14/18/25]

Diana
Shield: 325 (
) [275/325/515]
Shield: 280 (
) [230/280/450]

Samira
Passive Damage: 95 = 80 (
) + 15 (
) [55/80/130]
Passive Damage: 83 = 68 (
) + 15 (
) [45/68/115]

Morgana

Riven

Zed
Create a clone behind the target with 33/40/40% reduced max Health and 30 increased Mana cost. The clone inherits its creator's items, stats, and current Health, and can cast Quantum Clone.
Create a clone behind the target with 25/35/40% reduced max Health and 30 increased Mana cost. The clone inherits its creator's items, stats, and current Health, and can cast Quantum Clone.

Conduit

Biomatter Preserver
Gain 0% max Health and deploy 3 Life Orbs. Every 8 seconds of combat, one drops restoring 18% of the holder's missing Health.At (4): If the holder is Psionic, they gain 22% increased healing from all sources.Recommended user: Gragas. Gain 0% max Health and deploy 3 Life Orbs. Every 8 seconds of combat, one drops restoring 18% of the holder's missing Health.At (4): If the holder is Psionic, they gain 30% increased healing from all sources.Recommended user: Gragas. 
Drone Uplink
A drone repeats 25% of damage from the holder's attacks and Abilities to the same targets every 3 seconds.At (4): If the holder is Psionic, gain an additional mini-drone that repeats 20% of damage.Recommended users: Sona and Viktor. A drone repeats 25% of damage from the holder's attacks and Abilities to the same targets every 3 seconds.At (4): If the holder is Psionic, gain an additional mini-drone that repeats 30% of damage.Recommended users: Sona and Viktor. 
Malware Matrix
Attack Champion: Dealing physical damage to an enemy reduces the target's Armor by 2.Magic Champion: Dealing magic damage to an enemy reduces the target's Magic Resist by 2. At (4): If the holder is Psionic, every 3rd attack cleaves, dealing 75 (
) physical damage to nearby enemies.Recommended users: Master Yi and Pyke.Ability Damage Cooldown: 0.75 seconds. Attack Champion: Dealing physical damage to an enemy reduces the target's Armor by 2.Magic Champion: Dealing magic damage to an enemy reduces the target's Magic Resist by 2. At (4): If the holder is Psionic, every 3rd attack cleaves, dealing 75 (
) physical damage to nearby enemies.Recommended users: Master Yi and Pyke.Ability Damage Cooldown: 1 seconds. 
Target-Lock Optics
When the holder damages each enemy for the first time each combat, gain:Attack Champions: 9% Attack DamageMagic Champions: 7% Ability PowerAt (4): If the holder is Psionic, they heal 20% of their max Health whenever their target dies.Recommended users: Pyke and Master Yi When the holder damages each enemy for the first time each combat, gain:Attack Champions: 9% Attack DamageMagic Champions: 7% Ability PowerAt (4): If the holder is Psionic, they heal 30% of their max Health whenever their target dies.Recommended users: Pyke and Master Yi 
The Annihilator

Iceblast Armor
The first time you fall below 70% and 35% health, gain a 25% max health shield for 4 seconds and release a frost nova that stuns enemies within 3 hexes for 2 seconds.Recommended Roles: Attack or Magic Tank The first time you fall below 70% and 35% health, gain a 20% max health shield for 4 seconds and release a frost nova that stuns enemies within 3 hexes for 1.5 seconds.Recommended Roles: Attack or Magic Tank 
Lioness's Lament
Every 15% max health lost, fire crescent projectiles in a line dealing physical damage equal to 50% of the holder's Armor and Magic Resist. Steal 4 Armor and Magic Resist from all enemies hit.Recommended Roles: Attack or Magic Tank Every 15% max health lost, fire crescent projectiles in a line dealing physical damage equal to 50% of the holder's Armor and Magic Resist. Steal 3 Armor and Magic Resist from all enemies hit.Recommended Roles: Attack or Magic Tank 
Cosmic Restart
Call upon the Gods to sell all units on your board and bench. Gain 2 random Emblems and 8 free Shop rerolls.
Call upon the Gods to sell all units on your board and bench. Gain 2 random Emblems and 15 free Shop rerolls.