These were the balance changes we received in the Renovation Patch on the May 8th 2018 for NA/EU:

Seha
Hitbox reduced overall for Rush
Restand removed and range reduced for Burst
All of Seha's Skill Damage is reduced by 15%
Seha changes to Rush Master Cube augment: Using Rush grants a stack of “Exploding Rush”, and having 3 stacks will enhance your next Rush with an explosion attack (does True Damage, hits *very* hard)
FM2 landing hitbox increased
FM1 activation speed increased
Skyslash speed increased

Seulbi
Slight increase in the pre-cast delay on FM2
Bug fix on neutral cast enh Electric Storm having no Super Armour
Bug fix on magnetic infusion losing Super Armour mid cast

Yuri
Invulnerability removed from Lunging Slash
Travel distance + travel speed decreased for Supersonic Slash
Super Armor on extension for Rolling Vulcan
Spin-Kick Rapid Shot has Yuri move further forwards when used in air if a directional key is pressed, *however* this increase is negated by an overall nerf to range and speed moving forward in aerial use for the skill (overall smaller vertical hitbox but greater horizontal hitbox due to forward movement)
Invulnerability removed from Phase Flip
Instant invulnerability from aerial use removed from Yuri Star
Pre-cast delay before cast removed from Yuri Star
Aerial Yuri star's hitbox greatly increased; now performs follow up attack much faster
Other skills now cannot be used while being invulnerable during the cast of Yuri Star
FM2 is now performed much faster

J
Hit range on cast reduced for Germanium Power
Ground use dealing less damage than aerial fixed and damage ratio being more focused on multi-hit for Omega-3 Rush(Damage same as before overall)
Range and speed of moving forward in aerial use reduced for Ocher Catch
Damage ratio being more focused on multi-hit portion for FM1(Damage same as overall)
Range reduced for Jade Magnetism
Grab proc now only begins after the orb has traveled to the end(orb won't grab while it's moving forward) for Jade Magnetism
Grab proc in aerial use slightly reduced for Chiropractic
Force Cancel now usable during Body Massage

Mistiltein
30% Damage decreased in Lance Cruising
All damage including the sword reduced by 40% on Laevatein.
Einherjar Mode's Enhanced Magilance Niflheim: Wintry Spirit’s Phase Power recovery adjusted to 10%
Tornado bug fixed where Enhanced Midgard would disappear after the spin finishes
FM1 bug fixed where Super Armor would randomly disappear during cast

Nata
Delay for neck slash portion of Sure Kill reduced
Force Cancel now usable during FM1
FM1 is now an iframe
Hit proc removed from beginning of FM2
Pulverizing Blade now has 1.5 sec set duration
Endless Pursuit is full iframe (as opposed to only back and forth)
80% damage reduction added to Torrent of Pain
Guillotine and Punishment now are guaranteed Aerial procs when used on the ground
Fidget spinner now stays for a smaller duration when placed

Levia
Location designation now set for Designated Sacrifice & Dimensional Singularity & Hell's Trap
Movement speed during use in the air reduced for Snake Signet
Snake Signet vertical hitbox reduced
Hit proc being left over when the skill effect was gone fixed for FM2 & FM3
Expert Cube no longer applies in arena for Hell's Trap
Master Cube no longer applies in Arena for Mamushi Swarm
Snake Signet, Serpent Waltz and Flash of Pain now have guaranteed Back damage procs
Flash of Pain has its range increased by 30%

Tina
Chase proc from ground basic attack removed
Range on ground basic attack halved
Grenade's restand proc removed
Launch on upward attack removed
Invulnerability only during invisible portion for Dive
Travel distance in y-axis decreased for Dive
Pre-cast delay increased for Sharp Shooting
Travel speed decreased for Sharp Shooting
Grab-proc range decreased for Sharp Shooting
FM1 vertical hitbox reduced

The following changes came with the character re-balances that took place in April 2018 in Korea: https://docs.google.com/document/d/1yOO050_O8ywLakKmOzFqIIg-hkoEj3QZ-49vjKqW_Fg/edit#

Not all of these changes apply in PvP and here follows all those that do (or those that only partially work).
Unless stated otherwise *all damage increases and damage ratios do not translate into pvp*, whilst *all guaranteed Air/Back/Chase procs added to skills do apply in PvP*

All skill cubes *do* apply in PvP, even those that include damage increases or cooldown reduction (such as Yuri's Spin-Kick Rapid Shot/Yuri Spiral CD reduction), unless stated otherwise

For the sake of posterity, EX Skills have *not* been pruned and remain documented even if not yet present in NA/EU

Seulbi
Exploit Weakness: Bits changes all apply in PvP; this also includes the Special Agent Passive (Bits: Phase Amplification)
Magnetic Infusion has gotten a damage buff; the new "damage-on-hit" added to the skill does translate to PvP, as do all of its cubes
FM2's rework does apply in PvP; this include the increase in damage from damage ratio redistribution and the skill now works much like Levia's FM2, where it will linger as soon as it is cast, rather than needing to wait for the followup
Psychic Satellite does *not* gain an iframe in PvP and remains unchanged from its existing version
Wormhole changes fully translate into PvP but so too does its Bit consumption Expert cube
Space Elasticity damage ratio is either too insignificant to be of note or does not apply in PvP, however Bit generation on cast as well as its cubes do apply

Yuri
Lunging Slash's (Shift) revamped diagonal movement does apply in PvP; this is also true to all Swift Step changes (including the stat increases and buff changes), allowing for Yuri to use Lunging Slash twice in a row while moving diagonally in PvP
Rolling Vulcan's change does translate to PvP, allowing for Yuri to do two volleys worth of damage in a single spin
FM2 has been completely revamped into a new skill altogether: this skill does work in PvP and the old FM2 no longer exists; all cubes and changes to the skill apply in PvP and it has a sizeable hitbox, capable of hitting ceiling height from the ground
EX Automatic Fire infinite buff duration does apply in PvP; KEEP IN MIND THIS MEANS THAT ONCE IT IS USED, YURI CANNOT REGAIN HER REGULAR BULLETS UNTIL THE END OF THE ROUND, upon which case it will be reset

J
Magnesium Strike extension does apply in PvP
Chiropractic rework applies fully in PvP as well as its damage increase (granted all of its new followup attacks connect)
FM3 forced landing does apply in PvP
EX Hundred Punches (Omega-3 Rush) animation speed increase and Do Not Look Back! buff do apply in PvP as well as its additional strike - this kick seems to be able to restand

Harpy
Double jump retains Super Armour in PvP but does not get damage reduction or combat dodge iframe
Draw changes do apply in PvP
Excited Again buff duration increase does translate to PvP
FM2 changes do apply in PvP; in addition, there is no longer an AoE indicator/marker that shows the attack while Harpy is in air - the player can still tell their position from the green player marker on the floor, but the actual attack itself cannot be seen until landing
Four Cards changes apply in PvP
Interlude Squall changes all apply in PvP
EX Sonic Boom's forced grab cancel animation does translate to PvP
FM3 changes all apply to PvP

Tina
I Want To Be Alone cubes all apply to PvP, especially relevant with its Master Cube
All changes to Rapid Fire and Pot Shot translate to PvP, including new visuals, enhancements and cubes
Phantom Snipe revamp and standardisation does apply to PvP

The following changes came with the May 3rd 2018 Patch in Korea:

Nata
Endless Pursuit has its iframe duration *only on the final attack* reduced to 0.5s on ground and 0.2s on air
FM3 hitbox has been greatly reduced
Shadow Hunting iframe on successful hit reduced to 0.1s

Harpy
FM1 start to end cast animation greatly increased (overall speed of FM slowed down)
EX Wind Sting reduced movement distance
EX Sonic Boom reduced movement speed
FM2 now displays the area indicator once again (reversal of change from April 2018 patch) and had its movement speed reduced

Tina
Close Combat had its cooldown increased to 15s (9s at 40% CDR)

The following changes came with the May 18th 2018 Patch in Korea:

Seha
Rush: Revamped super armor. Reduced travel distance
Discharge: Revamped super armor
Sky Slash: Revamped super armor. Triggers aerial even when used on ground (Applies for both PvE and PvP)
Focus Fire: Revamped super armor
Flame Pulverization: Fixed an issue where grab resist was not applying at specific frames
Finishing Move: Storm Blade: Revamped super armor for extra activation portion
Finishing Move: Inferno Blade: Slightly increased time taken to perform the initial attack when used in air

Seulbi
Magnetic Field Emission: Slightly reduced hitbox upon cast

Yuri
Shift: Changed to only allow single cast
Finishing Move: Yuri Special: Slightly increased time taken to perform the initial attack
EX Automatic Fire: Fixed the buff overlapping issue when cast

J
Full Body Massage: Increased movement speed
Ocher Catch: Disabled directional change after grabbing an enemy on the ground. Reduced movement speed after grabbing an enemy on the ground
Calcium Charging: Added damage reduction effect even when used in air
Jade Magnetism: Removed restand effect from 'Jade Punch' and increased damage
Headache Acupressure Method: Changed damage mechanics. First hit immediately downs the target, followed up by a restanding hit that deals damage. Slightly lifts the target into the air upon hitting (applies for both PvE and PvP). Performs the restand but does no damage if used on an already downed target. Made the direction change while casting the skill to be smoother (applies for both PvE and PvP). Reduced the damage of 'Punch', 'Double Hook' and 'Uppercut'.
Vitamin Combination: Decreased 'Jab' damage
Finishing Move: Golden Time Again: Increased hitbox by 25%
Chiropractic: Removed restand from 'Body Blow' attack. Reduced overall hitbox. Reduced 'Grab and Slam Down' attack's movement distance
Finishing Move: Feel Like Flying: Increased movement speed
EX Calcium Charging: Removed restand
EX Omega Rush: Increased 'Consecutive Phase Punch' hitbox by 20%. Slightly reduced additional input attack's hitbox
EX Jade Magnetism: Increased 'Extreme Magnetism' damage

Misteltein
Finishing Move: Valhalla's Courtyard: Removed the effect where the cooldown was reduced based on skill level

Nata
Confirmation Kill: Slighty reduced 'Decapitation (Executioner)' attack's movement distance. Removed restand effect from 'Decapitation (Executioner)'
Endless Pursuit: Slighty reduced extra input activation period (0.6s to 0.3s)
EX Torrent of Pain: Slightly reduced hitbox. Reduced 'Executioner's Spin' damage
EX Guillotine: Revamped super armor
EX Punishment: Removed invulnerability state from 'Close Quarter Slash'

Levia
Demonic Release: Removed 'Dragon's Potential' buff from Union Arena
Serpent's Seal: Reduced skill duration by 1s. Slightly increased movement speed
Hell's Trap: Removed grab resist
Serpent's Waltz: Reduced damage of the enhanced version from 'EX Horn Gouge' expert cube
Tormenting Light: Reduced damage of the enhanced version from 'EX Dimensional Singularity' expert cube

Harpy
Sonic Boom: Slightly reduced the grab hitbox when used in air
Interlude Squall: Reduced the damage of the 2nd enhanced hit
Four Card: Reduced the damage of Joker activation
Finishing Move: Icarus Fall: Slightly reduced the delay between initial cast and landing attack
EX Sonic Boom: Removed invulnerability state from the fail grab attack (including when activated with down directional key)
Double Jump: Removed super armor

Tina
Basic Attack: Reduced the elevation level when dash attack is used in air
Rapid Fire: Reduced the elevation level when used in air
Trick Shot: Removed the invulnerability state that was being applied for a short duration when cast (about 0.6s)
Phantom Snipe: Removed the camera's zoom out effect
EX Thunderbolt: Reduced movement speed
Finishing Move: Peacemaker: Added a 0.15s delay to the initial slam attack when used in air. Disabled directional change after casting
Finishing Move: Finish Them: Removed 'Marking' damage. Damage now takes 0.25s more before being applied (does not apply any damage if skill is cancelled)

Violet
Exceed Basic Attack: Reduced all damage reduction effect from 60% to 40%. 'Exceed: Alter Ego' no longer applies for Enhanced Dash Attack / Enhanced Dash Jump Attack / Shining Fist / Radiant Fist
Burst Blade: Readjusted skill cooldown (15s / 9s with max cooldown reduction)
Finishing Move: Efflorescent Dance: Removed the invulnerability state at the end slash, after Violet reappears

Wolfgang
Starting Motion: Fixed the issue where the starting motion was slightly longer compared to others
Synchro - Darkmoon Slash: Increased movement speed for the invulnerability portion
Page of Manipulation: Removed invulnerability state from fail grab attack
EX Page of Manipulation: Removed invulnerability state from fail grab attack

Luna
Phase Power Release: Removed grab resist that was present
Magisword Harpe: Removed skill lock effect from 'Snake Hunt' attack
Meteor Jump: Slightly reduced movement speed
Zodiac's Protection: Fixed an issue where grab resist was not applying on certain frames

Soma
Starting Motion: Fixed the issue where the starting motion was slightly longer compared to others
Rakshasa's Karma: Reduced hitbox
Finishing Move: Agneyastra: Reduced hitbox