Quinn rework concept
It would be great to read the Thoughts after you read the rework for more information behind this rework.
Tag Team (Passive) Every few seconds enemies are marked as Vulnerable. Spots a Feather when Quinn hits the mark, the feather position works somewhat like Dravens axe. Stepping onto the_Feather_ will signal Valor to aid you, entering in Tag Team Mode for a short duration. You can extend Tag Team's duration by picking more Feathers. Feathers can stay on the ground for a long time and they can be destroyed by enemies by stepping on them. Proc'ing the mark wont deal bonus damage.
When using Tag Team: Some abilities can only be used in Tag Team. Quinn gains increased Movement/Attack speed and increased AA range by (40,70,100) according to R's levels. Valor will come to fight with you. He will have his own Attack and Attack Speed and will attack only champions or monsters. Valor's damage increases with Critical Chance. Ruthless Chain is available: Ruthless Chain (Passive inside a Passive--PassiveCeption) Quinn cannot critically strike generally or never. But when she is in Tag Team: Every consecutive AA on the same target will add a percentage of critical chance(%) until she crits. When she crits the chain resets to zero and starts again until she crits again. Valor's AA will add a stack of percentage critical chance to your chain too. Finally critical chance on Quinn gets converted (not all of it) into critical damage.
Q Skystrike: Quinn fires a projectile that splits in the air into smaller projectiles and damages an area. The area stays for a few seconds. Tag team ailities have some added effects if they are used in Skystrike area.
Tag Team Q Valor's First Wind: (Skillshot) Valor flies straight in a line dealing damage and causes dazzle on the 1st enemy it hits for a short duration. If its used in Skystrike it causes grievous wounds. Dazzle is a new effect that looks like a smoke cloud in the screen. examples: before (http://i.imgur.com/6zfHQ3g.jpg) after (http://i.imgur.com/4fPngaZ.jpg)
W Hightened Senses: Quinn orders Valor to reveal an area (like a blue trinket, big cooldown of 1 minute or so)
Tag Team W Valor's Second Wind: Valor attacks all enemies around you (Quinn base AA range) slowing heavily all enemies. If its used inside Skystrike area Valor penetrates some of the enemy's armor.
E Vault: Quinn dashes to an enemy and bounces off on the location of her choosing. Quinn's E works like Camille's E. She can stay about half a second on the target. She can be damaged and knocked away from the target. She doesnt knockback or slow anymore but she can cancel some abilities like before. She can pass terrain as before too. After bouncing the enemy becomes marked as Vulnerable and a Feather spawns behind her. Vault has a big cooldown (probably 30 seconds) but it gets reduced by a little bit by hitting criticals using Ruthless Chain or picking up Feathers.
R Valor's Last Wind: (Passive) When out of combat Valor picks up Quinn gaining out of combat movement speed. Has less MS than now and bigger cd, around at 1 minute. At the moment of death Valor sacrifices himself to save Quinn. If the damage is lethal, Quinn will gain some Health based on her AD. If Valor dies, Quinn cannot enter in Tag Team, so you cant use most of your skills. Valor will be able to aid you after a medium cooldown of 20 seconds but he wont be able to sacrifice himself for some minutes. *When Valor is around a shadow of a bird flying is near you, when he is "dead" the shadow is gone.
Final Assault: (R Active) Quinn marks an enemy for 11 seconds entering immediately in Tag Team (Tag Team's duration is different than the mark of Final Assault). Ruthless Chain percentage critical chance increases drastically against this marked target. Random feathers also spawn around you every 1.5 second, each refreshing the duration by a bit, enabling you to stay longer in Tag Team. Valor also gains attack speed and % armor penetration, the latter according to the enemy's missing hp. Killing the enemy increases the Tag Team's duration by 5 seconds and lets you Mark another enemy. During Final Assault other enemies, beside the marked one, cannot be marked as Vulnerable.
Thoughts
This champion's thematic is Teamwork. Teamwork between Quinn and Valor. Valor spots the vulnerable spot of an enemy and signals Quinn. Quinn picks up Valor's feather signaling that she is ready and they both engage. Together they stack up Ruthless Chain. When Quinn is in Tag Team she is really strong and versatile. Her kit is overloaded that time but thats why she needs Valor. Without him, she cant function and she is really weak. Feathers give a dynamic laning phase that give plenty of opportunities both to Quinn and to the opponent. Her movements are somewhat predictable because of the feathers. If one member of the team isnt there the other members will struggle.
Finally this concept of Quinn takes away some of her early game power and puts it later in the game. Her position should be best for bot. Critical chance items are the prefered items. She is overloaded when Valor is around but useless when he is not there.