Don't listen to the lux mains
"OMG LUX IS SO WEAK HER E COSTS 130 MANA!"
Hmmmm...an ult with the range of the diameter of your base on a low cool down. A long ass snare. An annoying passive. And a shield that costs 60 mana that gives a shield on the way forward and the way back. Not to mention she is incredibly easy to play and you have to be a total dipshit to get caught in the early game.
Stop complaining. If anything she is actually one of the top mages at the moment. If she gets too strong she will get nerfed into the ground.
The 130 mana cost is there so that when you play Lux you actually have to have a brain and manage your mana.
and get
and CDR Quints/glyphs. If you're not able to waveclear with her E... this is why. You're not building the firepower.