Proposed changes to Katarina to make her less OP while keeping her power level roughly the same. . .

2 words. Mana Costs.

Giving Katarina mana means a LOT of things. 1) she can't stay in lane and farm forever 2) She has to manage a resource so that she can damage and trade effectively. 3) She can run out of mana so she can't reset an entire team my smashing her face on her keyboard after a kill 4) You can keep her kit roughly the same power wise(maybe even buff her numbers a little bit so that it coincides with the amount of mana she is spending)

Because honestly, balancing her is such an issue because she is resourceless. She doesnt have to have blue buff(although CDR does help) to stay in lane. She can't build mana items at all to use them(hello tear of the goddess and seraph's embrace, Kat would like to love you) and this affects other lanes/jungler as well in terms of gameplay.

Also this means that her kit would have a bit more counterplay, meaning if you can get her to waste enough mana that her escape(shunpo(which should be her highest mana cost)) is not available, she either has to go back or risk getting dove since her escape is down.

Thoughts? I think Katarina would be a lot more...well...fun if she had mana and mana costs to her abilities. She can keep her passive, and no changes need to be implemented on her abilities. This would open up several more buildpaths on her as well.