A guide to picking your champion when facing Lux
Since Lux will soon become very popular, I would like to look into what champions to pick against her http://i.imgur.com/9PBcVQQ.jpg
A: is a water type. Use electric type and grass type pokemon when facing her while avoiding fire types.
Good choices:
Bad Choices:

B: A grass type. Unlike A, fire and ice types as well as poison types are really good against her but water types and rock types are a big nono.
Good:
Bad:

C: Flying type: Use electric and rock types versus this form while avoiding fighting and grass types
Good:
Bad:

D: Fire type. Fire types are weak to ground and rock type champions while strong against ice, bug and steel
Good:
Bad:

E: A Dark type. Use Fairy type and fighting type attacks. Avoid Psychic types as they have no affect on her. Also has good resistance vs dark types
Good:
Bad:

F: Psychic Type. Ghost types are super effective along with dark types. Don't use fighting types or poison.
Good:
Bad:

G: Seems like a dual type of rock/fire. Best types are water and ground. Avoid using fire and normal types as you only deal 1/4 and 1/2 damage respectavely.
Good:
Bad:

H: Electric Type. This one is tough as her only weakness is ground type. Flying types are not advised when fighting her.
Good:
Bad:

I: Fairy Type. Use poison and steel types. avoid dragon types as they deal no damage to her
Good:
Bad:

J: Finally the ice type. Best choice would be Fire and Fighting. Grass and Flying will have trouble though
Good:
Bad:

Final Note: Riot has nnot announced it but it may seem like almost all of the Lux's forms will be dual types with psychic as their 2nd type. In which case I would look at F for what to use.