Blade & Soul Korea 18th June update on assassin skill changes is highlighted. Similar changes have been applied to test server of Blade and Soul on the same day. The translation is based on the brief list of skill changes provided by Blade & Soul China.
Shadow Kill [F] – Disruption Stance
* new skill tree introduced in Cutthroat skill tree.
* deal massive dmg on targets with 5 layer of poison.
* can be used after Heart Stab (RB) deals crit damage.
Lightning Kill [F] – Stealth Stance
* new skill, which recover MP
* can be used after Heart Stab deals crit dmg in Stealth stance; maintain invisibility.
Lightning Step 
* deal additional damage on poisoned target
* deal massive explosion damage for each layer of poison status
* convert to Disruption Stance after cast.
Shadowless Step 
* the skill tree is separated from Lotus Dance [C]
* Stun enemies when used in Stealth Stance; go into Stealth for 6sec after casting
* new effect after leveling – target cannot use charging skill, reduce movement speed, disabling of vision and hearing.
Heart Stab [RB]
* new effect after leveling – maintain stealth after using heart stab
* instant cast when in stealth stance
* instant cast on target with abnormal status
* instant cast on target with 5 layers of poison
Back Stab [LB] – Stealth Stance
* remove aoe dmg dealing effect
Mist Slash [LB] – Disruption Stance
* level 5 effect change: after dealing crit, the next Heart Stab [RB] 100% deal crit dmg.
Shadow Slash 
* Rank 1 path: deal additional damage to enemies with poison or abnormal status; increase chances to stack poison effect.
Timer Bomb  – Stealth Stance
* Recover 9 MP over 3sec when ignite with Mine, Throwing Mine
Single Blow [TAB] – Steath Stance
* Change to DPS skill
* convert to Discruption Stance after cast.
Shadow Invasion [TAB]
* Remove Shadow effect
* Upon hitting poisoned enemies, go into Stealth stance for 6sec.
Lightning Dagger 
* new DPS skill tree added
* Rank 1 path: Stun enemies, and recover MP according to the number of targets
* Rank 2 path: DPS skill path, recover MP after dealing crit.
Shadow Step [X]
* Shadow Step is separated from Shuriken skill tree
* Rank 1: MP recovery path for PVE
* Rank 2: Disabling path for PVP; chance to stun enemy; 100% stun on target with 5 layers of poison
Poison Dagger [X]
* new skill for poison stacking
* can be used after resisting damage.