Talon rework concept, from a Level 7 Talon main

Passive: Mercy: Talon pities his targets suffering, so he makes sure they die quickly. Talon's damaging abilities deal 10% additional damage to targets under 50% max HP, increasing to 20% when they're at 10% max HP.

Q: Noxian Diplomacy: Talon's next basic attack deals 30 / 60 / 90 / 120 / 150 (+ 30% Bonus AD) as bonus physical damage damage. If Talon uses this ability on a target, and reduces their HP to 5% or less, that target instantly dies instead.

W: Rake: No change.

E: Cutthroat: Passive: If Talon has not attacked 6 seconds, he gains 20 / 30 / 40 / 50% bonus movement speed, and ignores unit collision. If Talon takes damage from a champion or large monster, the bonus is halved for 3 seconds.

Active: Talon marks an enemy champion with Du Couteau's Regards for 4 seconds. When moving towards a marked champion, Talon gains 20 / 30 / 40 / 50% additional movement speed. Additionally, marked targets take 10% additional damage from Talon.

R: Shadow Assault: After a brief delay of not taking damage, or 3 seconds if he does take damage, Talon becomes stealthed and instantly gains Cutthroat's passive movement speed bonus. While stealthed from Shadow Assault, Talon's next basic attack will teleport him behind his target, and send out a ring of blades. (Like his Live ult) The blades deal 120 / 170 / 220 (+65% of his bonus AD) physical damage whenever they move, and passively deal 25 / 50 / 75 (+10% of his bonus AD) physical damage per second to anyone that's standing in them. If Talon kills the enemy he teleported to, or reactivates this ability, the blades shoot back into him, and he becomes stealthed for 2 seconds. This new stealth will not send out blades like the previous. While Talon is stealthed, enemies will receive a "!" if he is running TOWARDS them in about 1000 units.

Numeric values subject to change, since this could be pretty broken with these number values.