Siege, The lorn dagger

While at work i was brainstorming champion ideas, this is my best one, very simple and straightforward champion with high potential and one hit ko! (on most targets)

Role: AD Assassin Energy based

(Passive) Assassins Vigor: Landing an ability on a champion grants critical strike chance and applies a stack of Focus to the target, stacking up to 5 times. Basic attacks refresh the duration. Critical strikes restore energy.

(Q) Honed Dagger: Medium range skillshot that deals AD damage, low cooldown.

(Suggestions wanted) (W) Widow Spike: Refreshes basic attack, Siege's next basic attack applies a slow and increased AD damage. Critical strike amplifies the slow, Moderate cooldown.

(E) Shadow Step: Rapidly Dashes a short distance, granting Invisibility very briefly (only during the dash). Landing an ability on a champion refreshes the cooldown. If Siege has 5 stacks of Assassins vigor, the dash also applies a slow if he dashes through a champion. Moderate cooldown. This ability does not affect Siege's passive nor does it reset Shadow Step's cooldown.

(R) Flesh's Demise: (Skillshot) Siege brandishes his weapon, then lunges forward (Invisible?) with weapon extended, Dealing heavy AD damage that increases based on Focus stacks (5%/stack). If the target has 5 stacks of focus and gets struck from behind, Flesh's Demise deals true damage instead.

Siege is a reflex based champion that relies on precision and control. His primary ability is his (E) to stick to his targets and to keep him alive during teamfights, while his Q and W primarily focus on Refreshing his E and positioning him to land his ult on squishier targets. Ill Leave the Lore and Balancing to Riot.