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: Feb 23 4AM

Atakhan

Frozen Tower

Golem

Sand Soldier

Senna

Shyvana

Training Dummy

Anivia

Blitzcrank

Briar

Caitlyn

Illaoi

Jarvan IV

Jhin

Kog'Maw

Lulu

Qiyana

Rumble

Shen

Sona

Viego

Aphelios

Ashe

Cho'Gath

Ekko

Neeko

Rek'Sai

Sion
Shield: 272 = 4%
+ 225 (
) [200/225/250]
Damage: 47 (
) [4/4/4]
Shield: 225 = 4%
+ 225 (
) [200/225/250]
Damage: 0 (
) [4/4/4]

Teemo

Tristana

Twisted Fate

Vi

Xin Zhao

Yasuo

Ahri
Heal: 523 = 15%
+ 280 (
) [210/280/420]
Heal: 280 = 15%
+ 280 (
) [210/280/420]

Dr. Mundo
Bulk up for 5 seconds. While bulked, restore 114/192/325 (
) Health every second and attacks deal 105/171/291 (
) physical damage.
Bulk up for 5 seconds. While bulked, restore 60/95/150 (
) Health every second and attacks deal 60/90/145 (
) physical damage.

Draven

Gangplank

Jinx
Self Heal: 445 = 12%
+ 240 (
) [180/240/300]
Self Heal: 240 = 12%
+ 240 (
) [180/240/300]

Leona

Loris

Malzahar

Milio

Nautilus
Damage: 68 (
) [90/135/215]
Shield: 562 = 10%
+ 400 (
) [375/400/425]
Damage: 0 (
) [90/135/215]
Shield: 400 = 10%
+ 400 (
) [375/400/425]

Sejuani

Vayne

Zoe

Ambessa

Bel'Veth

Braum
Secondary Damage: 210 (
) [140/210/1350]
Secondary Damage: 240 (
) [160/240/1500]

Garen

Lissandra

Lux

Miss Fortune
Jump on an adjacent enemy with the lowest health, then deal 320/500/2000 (
) magic damage to them and 100/150/600 (
) magic damage to adjacent enemies. If any die, cast again, dealing 70% damage.Tanks take 60% more damage from this ability and Fighters take 30% more.
Damage: 500 (
) [320/500/2000]
Jump on an adjacent enemy with the lowest health, then deal 290/470/2000 (
) magic damage to them and 100/150/600 (
) magic damage to adjacent enemies. If any die, cast again, dealing 70% damage.Tanks take 60% more damage from this ability and Fighters take 30% more.
Damage: 470 (
) [290/470/2000]

Seraphine
Passive: All allies gain 10/20/100 Armor.Active: Gain 750/950/3000 (
) Shield for 4 seconds. Impale up to three nearby enemies in a line, dealing 84/126/1750 (
) physical damage and Stunning them for 1.5/1.75/8 seconds.
Damage: 126 (
) [120/180/2500]
Passive: All allies gain 10/20/100 Armor.Active: Gain 750/950/3000 (
) Shield for 4 seconds. Impale up to three nearby enemies in a line, dealing 0 (
) physical damage and Stunning them for 1.5/1.75/8 seconds.
Damage: 0 (
) [120/180/2500]

Swain
Heal: 52 = 1.5%
+ 20 (
) [18/20/100]
Heal: 20 = 1.5%
+ 20 (
) [18/20/100]

Taric

Wukong
Copy Health: 956 = 40%
+ 200 [150/200/2000]
Copy Health: 200 = 40%
+ 200 [150/200/2000]
Bonus Physical Damage: 120 (
) [80/120/800]
Bonus Magic Damage: 210 (
) [140/210/1400]
Split Damage: 480 = 240 (
) + 240 (
) [160/240/1080]
Bonus Physical Damage: 105 (
) [65/105/800]
Bonus Magic Damage: 190 (
) [125/190/1400]
Split Damage: 450 = 210 (
) + 240 (
) [140/210/1080]

Yunara
Slash Damage: 210 = 185 (
) + 25 (
) [95/185/2400]
Swipe Damage: 252 = 120% of 210
Slam Damage: 336 = 160% of 210
Slash Damage: 195 = 170 (
) + 25 (
) [85/170/2400]
Swipe Damage: 234 = 120% of 195
Slam Damage: 312 = 160% of 195

Annie

Azir
Passive: After witnessing 3 attacks from Azir, Sand Soldiers deal 100/150/3000 (
) magic damage to their target.Active: Summon a Sand Soldier near target and command them to strike. If 2 Soldiers are already out, they all immediately deal 70/105/5000 (
) magic damage instead.
Secondary Damage: 105 (
) [70/105/5000]
Passive: After witnessing 3 attacks from Azir, Sand Soldiers deal 100/150/3000 (
) magic damage to their target.Active: Summon a Sand Soldier near target and command them to strike. If 2 Soldiers are already out, they all immediately deal 90/135/5000 (
) magic damage instead.
Secondary Damage: 135 (
) [90/135/5000]
Slam Damage: 265 = 2%
+ 200 (
) [150/200/1500]
Slam Damage: 200 = 2%
+ 200 (
) [150/200/1500]

Fiddlesticks
Passive Damage: 371 (
) [380/570/9000]
Crash Damage: 488 = 525% (
) + 225% (
) [350/525/5000]
Passive Damage: 0 (
) [380/570/9000]
Crash Damage: 0 = 525% (
) + 225% (
) [350/525/5000]

Kindred

Lucian & Senna

Ornn
Release a runic blast, dealing 235/425/1500 (
) magic damage. It splits in two, dealing 33% of the damage to the closest two enemies. Each secondary blast splits an additional time.Bilgewater: Blasts explode on impact, dealing 25% of the damage as physical damage to adjacent enemies.Demacia: Execute targets below 12% (
) Health.Freljord: Chill targets for 4 seconds and deal 60/108/194 (
) bonus true damage.Ionia: Blasts split an additional time, dealing 50% damage.Ixtal: Gain a random Region's effect on combat start and every 10 seconds.Noxus: Blasts now pierce targets, dealing 60% reduced damage per enemy hit.Piltover: Every third cast is Overcharged, dealing 40% more damage.Shadow Isles: Increase blast damage by 5% (
).Shurima: Knock up enemies for 0.5 seconds, with a chance to dredge up Gold or Treasures.Targon: Heal the lowest Health ally for 10% of the damage dealt.Void: Ignore 30% of enemies' Armor and Magic Resistance.Yordle: Shrink targets hit, lowering their damage by 12% percent for 4 seconds.Zaun: Poison targets, dealing 15/30/500 magic damage 3 (
) times over 4 seconds.
Freljord Damage: 108 = 6% max 
Release a runic blast, dealing 235/425/1500 (
) magic damage. It splits in two, dealing 33% of the damage to the closest two enemies. Each secondary blast splits an additional time.Bilgewater: Blasts explode on impact, dealing 25% of the damage as physical damage to adjacent enemies.Demacia: Execute targets below 12% (
) Health.Freljord: Chill targets for 4 seconds and deal 0 (
) bonus true damage.Ionia: Blasts split an additional time, dealing 50% damage.Ixtal: Gain a random Region's effect on combat start and every 10 seconds.Noxus: Blasts now pierce targets, dealing 60% reduced damage per enemy hit.Piltover: Every third cast is Overcharged, dealing 40% more damage.Shadow Isles: Increase blast damage by 5% (
).Shurima: Knock up enemies for 0.5 seconds, with a chance to dredge up Gold or Treasures.Targon: Heal the lowest Health ally for 10% of the damage dealt.Void: Ignore 30% of enemies' Armor and Magic Resistance.Yordle: Shrink targets hit, lowering their damage by 12% percent for 4 seconds.Zaun: Poison targets, dealing 15/30/500 magic damage 3 (
) times over 4 seconds.
Freljord Damage: 0 = 6% max 

Shyvana
Shield: 652 = 10%
+ 400 [300/400/66666]
Laser Damage: 555 = 540 (
) + 15 (
) [360/540/2000]
Missile Damage: 56 = 10% of 555
Shield: 400 = 10%
+ 400 [300/400/66666]
Laser Damage: 495 = 480 (
) + 15 (
) [320/480/2000]
Missile Damage: 50 = 10% of 495
Passive Drain: 50 = 50 (
) + 1 per 15 
[30/50/400]
Passive Drain: 56 = 56 (
) + 1 per 30 
[37/56/400]

Tibbers
Passive: After attacking an enemy, restore 38/68/4860 (
) Health. If they are Burning, the healing is doubled.Active: Gain 200/200/500% Attack Speed and 1000/1200/9000 (
) Shield that decays over 4 seconds. Gain immunity to Crowd Control effects for the same duration.
Heal: 68 (
) [2.5/2.5/100]
Passive: After attacking an enemy, restore 0 (
) Health. If they are Burning, the healing is doubled.Active: Gain 200/200/500% Attack Speed and 1000/1200/9000 (
) Shield that decays over 4 seconds. Gain immunity to Crowd Control effects for the same duration.
Heal: 0 (
) [2.5/2.5/100]
Bite Damage: 215 = 3%
+ 150 (
) [100/150/2000]
Slam Damage: 430 = 200% of 215
Bolt Damage: 161 = 4%
+ 75 (
) [50/75/999]
Bite Damage: 150 = 3%
+ 150 (
) [100/150/2000]
Slam Damage: 300 = 200% of 150
Bolt Damage: 75 = 4%
+ 75 (
) [50/75/999]

Zilean

Ascendant
After each combat, an Ascendant Charm appears in your shop. These are powerful effects that can be bought for gold.0
After each combat, an Ascendant Charm appears in your shop. These are powerful effects that can be bought for gold.0<ShowIfCustom.Set=TFTSetEventCT>In Choncc's Treasure, the Fateful Find Charm and the Faithful Followers Charm cannot appear until you are level 7.</ShowIfCustom.Set=TFTSetEventCT> 
Bruiser

Chronokeeper
Every 2 casts, the Chronokeeper stores 1 XP. If he has enough stored for you to level up, he transfers you the required XP. If you are level 10, he instead gains 15% Damage Amp.Stored XP: 0 Every 2 casts, the Chronokeeper stores 1 XP. If he has enough stored for you to level up, he transfers you the required XP. If you are level 10, he instead gains 15% Damage Amp.Stored XP: 0<ShowIfCustom.Set=TFTSetEventCT>In Choncc's Treasure, the amount of casts required to gain XP is increased to 4 until Stage 3-5.</ShowIfCustom.Set=TFTSetEventCT> 
Shurima
Each second, Shurimans gain 2% Attack Speed and restore 20 Health. At combat start, they gain additional effects.(2) 20% max Health
(3) 50 Armor and Magic Resist
(4) A Shuriman ascends to GODHOOD every 3 seconds.
Each second, Shurimans gain 2% Attack Speed and restore 20 Health. At combat start, they gain additional effects.<ShowIfCustom.Set=TFTSetEventCT><ShowIf.TFT16_Shurima_NoPrismatic>Prismatic: Unlock Nasus, Renekton, and Xerath, then field 4 Shurima</ShowIf.TFT16_Shurima_NoPrismatic></ShowIfCustom.Set=TFTSetEventCT>(2) 20% max Health
(3) 50 Armor and Magic Resist
(4) <ShowIf.TFT16_Shurima_PrismaticActive>A Shuriman ascends to GODHOOD every 3 seconds </ShowIf.TFT16_Shurima_PrismaticActive><ShowIfCustom.Set=TFTSetEventCT><ShowIf.TFT16_Shurima_NoPrismatic>Only available when Nasus, Renekton, and Xerath have been unlocked.</ShowIf.TFT16_Shurima_NoPrismatic></ShowIfCustom.Set=TFTSetEventCT>

Slayer

Adrenaline Modules
Gain 15% Damage Amp, increased by 1% after every 3 attacks.Recommended users: Bel'Veth and Kai'sa Gain 20% Damage Amp, increased by 1% after every 3 attacks.Recommended users: Bel'Veth and Kai'sa 
Leeching Nucleus
Heal the lowest Health ally for 15% of damage dealt. After damaging an enemy, steal 2% Attack Damage and Ability Power from them, up to 15 stacks from all sources.Recommended users: Kog'Maw, Malzahar, and Kai'sa Heal the lowest Health ally for 15% of damage dealt. After damaging an enemy, steal 2% Attack Damage and Ability Power from them, up to 10 stacks from all sources.Recommended users: Kog'Maw, Malzahar, and Kai'sa 
Bandle Bounty I
For every Yordle you've unlocked or unlock, gain 2 gold. The Bandle Paths reveal a secret Yordle 10. Gain a Rumble and Lulu.
Reach level 10 and field 10 unique Yordles to reveal the Bandle Path's secret. Gain a Lulu and a Rumble.

Bandle Bounty II
For every Yordle you've unlocked or unlock, gain 4 gold. The Bandle Paths reveal a secret Yordle 10! Gain a Tristana and Teemo.
For every Yordle you've unlocked or unlock, gain 2 gold. Reach level 10 and field 10 unique Yordles to reveal the Bandle Path's secret. Gain a Tristana and Teemo.

Walk The True Path I
Gain a Lesser Champion Duplicator, a Shen, a Jhin, and 6 gold. Ionia 10 gains a Prismatic upgrade.
Gain a Lesser Champion Duplicator and a Yasuo. Reach level 10 and field 10 unique Ionians to unlock a Prismatic Upgrade.

Walk The True Path II
Gain 2 Lesser Champion Duplicators, a Jhin, a Shen, and an Infinity Edge. Ionia 10 gains a Prismatic upgrade.
Gain 2 Lesser Champion Duplicators, a Yasuo, and a B.F. Sword. Reach level 10 and field 10 unique Ionians to unlock a Prismatic Upgrade.