IMO she is very OP, what are your thoughts?
Katarina is like...the Charizard of LoL champions.
New players think she's OP and the best thing ever.
Experienced players no better.
Katarina has her moments: but she's objectively much worse than she appears subjectively. Her kit has no team-wide benefits or utilities, disabling her mid-ult shuts down her kit pretty hard, Katarina's play-style involving throwing herself in the middle of 3 enemy champions is extremely risky, Katarina's lanning phase is fairly weak and she relies heavily on roaming to do things, Katarina is completely useless if behind, and Katarina is generally feast or famine.
She's unreliable, and good champions in ranked generally have reliability and consistency as their biggest strong points.
The main thing Katarina has going for her is that all her power is really obvious and up-front. The rewards of Katarina using a skill or pulling off a combo are instantaneous. There's no hidden buffs or debuffs that need to be kept in mind, no combo interactions or strategic uses of her skills, no poisons or counter-shields. It's just extremely obvious, up-front, transparent, honest damage and speed.
When you're newer to the game and have no solid grounding or experiance to base a lot of delayed effects/buffs/debuffs/strategic moves, Katarina's up-front kit seems really strong.