Who for midlane?

Akali by far.her kit is useful in most matchups whereas Katrina has a lot of counters/counterplay. If you are far better than players in your elo Kat will serve you well but if you climb you will be shut down easily. Alkali has a kit that is pretty overloaded and will never be really bad unless they rework her. Kat is one of the champions who can succeed if the meta allows it if they buff her or the items she likes. Alkali is far superior in survivability and mobility. She has spellvamp oin her passive with high dmg ratios to win trades and a get out of jail free card with her shroud. Katharina needs to kill super fast or she's dead and if she gets cc'ed shes basically done.

Shit ton of dashes, shit ton of healing, shit ton of damage, and can go invisible for EIGHT SECONDS after any other champ wastes their ults which usually last less than eight seconds