[Champion - Assassin] F

Lore: F is an assassin. F has a dark and mysterious past. F takes pride in his work, and thinks Rengar ain't shit. F is the real world's best hunter.

(X does not have to be constant, X just serves as a placeholder number)

Passive - Ego: F deals X% reduced damage for each nearby allied champion, and deals X% increased damage for each nearby enemy champion.

Q - Stab stab stab: Passive: Successive attacks against a single target deal an additional X damage. Active: Next AA has bonus range, briefly slows the target and deals bonus damage, with the slow and damage increasing based on the number of Q stacks on the target.

W - Smoking kills: F lays down a cloud of smoke, dealing a small amount of damage to enemy units on cast. All units, allied or enemy, can enter the cloud, becoming hidden to units outside the smoke, at the cost of greatly reduced vision radius.

E - Swiggity Swooty...: F vanishes and becomes untargetable very briefly before re appearing at the target location. Upon kill (he's cocky and works alone, so assists don't count) CD refreshes.

R - "You're Mine!": F marks target enemy champion he will attempt to execute. After a brief delay, target champion becomes challenged for X seconds. During this time, F and his target cannot receive buffs from allies, including shields and heals, are immune to any damage (but not CC) not from each other and cannot move more than X units away from each other. During the duration, each champion also receives a MS buff whilst moving toward the other. At the end of the duration, if F has not executed his target, he loses health proportional to the current health of the marked enemy.

Q and W could probably use some work, but I'd really like to see the rest of his kit at work. Thoughts?