Unnamed Champion

I just came up with a basic outline about the champions abilities and wanted some quick technical feed back. I would like to say this is my first time on the boards and if my idea sounds similar to yours or someone else's I'm sorry I didn't take it I swear. And here it is for your critique.

Passive- Armor Piercing Bullets Basic attacks have armor penetration (scaling with critical chance)

Q-Quick Hands Passively increases reload speed. Activate to gain bonus attack speed

W-Till The Last/Final request Passive gain bonus physical damage and armor based of missing health. Activate all damage is true damage and Armor Piercing Bullets bonus armor penetration becomes critical chance. Takes 2 seconds to activate and drains Life while active a max of 10 seconds and can be activated again to deactivate it. Can kill you.

E-Quick Draw Passive when out of combat for 5 seconds gun is reloaded and holstered. Next attack has a 0.5 second delay and gains bonus life steal.

R-Duelers Prided Pair Activate you and target champion duel each other with single shot pistols. After three seconds you and target hero can either wait to fire or fire pressing R. Waiting increases damage upon firing deals true damage at the other champion and then they attack you unless they were killed. Other Champions can not interact with the duelers.

I'm looking for feed back about the basic question of "is it overpowered" and also some specific numbers for the abilities and/or formulas to the leveling process/where I can find the formulas for future champions I make. Thank you for the time.