Pretty crazy champ idea
Ok so I'm not going to make a serious back story so lets just say shes a wraith and her name is Rachel. Rachel being a wraith and all has no armor or magic resist and instead has a flat 50% damage reduction from all damage even true damage. She also doesn't do any damage at all on auto attacks instead she marks a target with a stacking debuff every time she auto attacks so natural all AP,AD,MR or armor will instead just increase her atk speed. Now, her 3 abilities will determine what debuff she is causing to target. Q could be movement and atk speed, B could be armor and MR and E could AP and AD. So basically every time she auto's she causes the person the become weaker and weaker but to make things balanced lets say that any single stack will only last for like 5 or 10 sec.. that way it can stack but it has a soft limit. This will make her scale a bit with her atk speed so when she is low she isn't debuffing the ever living shit out of people. Now for her ult. Her ult will be like a point and click nuke with a semi slow travel speed so that players have time to prepare for it. It will do like 250 damage to the targets very soul mitigated by nothing but heath. It wont scale and it wont increase with lvl. just a flat 250 damage. The "very soul" part means that it can kill people it shouldn't be able to Zil ulty, trynd, kindreded ulty, you get the idea. It also can't be blocked by shields. So thats the basic lay out. You could have her be lucian wife who escaped the latern if you want a decent back story but for the most part she supose to be support debuff mage. I didnt put in any numbers on how much each auto should reduce what ability because you cant really tell what is to strong or to weak till you test it and I think everyone can agree that this Idea will probably be hard as hell to balance already. Anyways, hope you like the idea and if you don't, Im a big boy Im not gonna start crying and flame anyone however I will ask that you give a reason or maybe an idea to improve as random insults are just kind of a waste of time. thanks guys