New champ Idea to fill the needs for a Cowboy adc that isn't Graves

Name - Chance Passive - Back to the Sun Enemies facing Chance have reduced attack speed/movement speed, reducing both by 10%

Q - Evasive Maneuvers Chance rolls to the left or right, gaining attack speed after exiting the roll.

W - Draw Chance fires a point and click shot, doing damage based upon the target's missing health. Can crit.

E - Bang! Chance rolls a stick of dynamite towards a designated area, damaging and slowing enemies for 1.25 seconds.

R - Stand Off Chance targets an enemy champion, making himself and the target invulnerable to all damage except for each other. He and the target only have vision of each other, and Chance gains a re-castable R that shoots out 6 skill shots, each doing more damage than the last and passing through all units except for the target. His Q cooldown is reduced by half during this time, his 6th shot crits, and after 6 shots or if one dies, the effect ends.

Let me know what you guys think, this is my first post here.