How do you get more creative with dive champs? You don't really. Lee Sin's about as good as you're going to get for Divers.
Her Q is one of the most unique dash tools in the game.
Her E is one of the only non-terrain conditional stuns in the game. She has to play around her Q in order to use it well.
The only exceedingly boring part of her kit is her W
Her ult fails from both a gameplay and theme standpoint because she doesn't build high AD like originally intended, and all she does with floating swords is chuck them at people to proc sheen rather than the other functionalities of it.
There are many ways to improve her kit, adding both gameplay for opponents to work around and giving Irelia more build diversity, but to say she's boring and generic is a flat out lie, considering the rest of the roster.
Mages are much more generic overall, even after their 'reworks'. Generic AoE waveclear ability, generic low CD damage ability (probably has a slow attached), generic CC. The main thing that differentiates most of them is their passive/ult.