Time to tilt all the anti-Assassin kids.
P: Blade's End 
https://vignette.wikia.nocookie.net/leagueoflegends/images/7/74/Blade%27s_End.png/revision/latest?cb=20170818195032
X champion's abilities wound enemy champions and epic monsters every time they deal damage, lasting 6 seconds and stacking up to 3 times.
X champion's basic attacks against enemies with 3 wounds consumes them, causing them to bleed for 75 - 245 (based on level) (+ 200% bonus AD) physical damage over 2 seconds.
Q: Rake 
https://vignette.wikia.nocookie.net/leagueoflegends/images/b/bd/Rake.png/revision/latest?cb=20170818195054
X champion sends out a volley of daggers, dealing physical damage to every enemy they pass through.
The daggers linger for 0.75 seconds before flying back to X champion, dealing physical damage to every enemy they pass through and Slow icon slowing them for 1 second.
W: Death Mark 
https://vignette.wikia.nocookie.net/leagueoflegends/images/3/34/Death_Mark.png/revision/latest?cb=20130929123513
FIRST CAST: X champion vanishes for 0.75 seconds during which they go through the target enemy champion, marking them, becoming ghosted for 3 seconds, and spawning a Shadow at the cast location which lasts for 6 seconds. After 0.5 seconds of X champion's reappearance they can activate Death Mark Shadow.
For the next 3 seconds, the mark stores a percentage of all pre-mitigation physical and magic damage X champion deals to the target, detonating at the end of the duration to deal physical damage.
https://vignette.wikia.nocookie.net/leagueoflegends/images/6/67/Death_Mark_2.png/revision/latest?cb=20171221052522
SECOND CAST - DEATH MARK SHADOW: Regardless of distance between each other, X champion and the Death Mark Shadow blink to their respective locations, swapping places.
https://vignette.wikia.nocookie.net/leagueoflegends/images/b/b5/Reaper_of_Shadows.png/revision/latest?cb=20170818200520
PASSIVE - REAPER OF SHADOWS: Scoring a takedown on a marked target permanently grants X champion bonus attack damage. The bonus gets replaced if X champion scores a takedown on a bigger valued target.
E: Shadow Step 
https://vignette.wikia.nocookie.net/leagueoflegends/images/1/19/Shadow_Step_A.png/revision/latest?cb=20171221043427
X champion removes slows and makes them immune to them for 5 / 6 / 7 / 8 / 9 seconds. Additionally, entering terrain will grant X champion movement speed to 70% for the remaining duration.
X champion heals himself upon moving through terrain for the first time and, if he's not in combat with enemy champions, Shadow Step's duration is increased. While inside terrain, X champion's vision pierces all obstructions although cannot see into brush.
Entering combat with a champion after the effect is enhanced reduces the remaining duration to 1.5 seconds. The effect also cannot remain active out of terrain for longer than 1.5 seconds.
R: Death From Below https://vignette.wikia.nocookie.net/leagueoflegends/images/4/43/Gift_of_the_Drowned_Ones.png/revision/latest?cb=20180516185330 (using as substitute picture bc no official icon on Boards yet)
https://vignette.wikia.nocookie.net/leagueoflegends/images/8/85/Death_from_Below.png/revision/latest?cb=20180516185259
X champion strikes in an X-shaped area, executing enemies below 190 - 655 (based on level) (+ 60% bonus AD) health while dealing the same amount as physical damage to enemies not within the threshold for execution.
If Death from Below hits an enemy champion, X champion will blink to the center of the X. If an enemy champion dies in the X, the assisting ally is granted full kill gold, and X champion gains the ability to recast within 20 seconds at no cost.