They're only loosely based on Marisa.

Spellthief Lux is a reference to Marisa's habit of stealing Spellcards.
Sorceress Lux is only similar to Marisa in that they're both Witches.

Lux still needs a true Marisa skin, preferably Legendary.
And Bump.

-MarisaØKirisame

They could make it the next theme

You mean Pulsefire Ezrael would have someone else to hang out with in that big lonely "Themes" tab?

Or are you just suggesting that so it'll be really expensive.

In the name of Touhou, all my want!

BUMP!
i dont think Sorceress Lux is based on Marisa's art. We want that black "maid" dress, the cute hat and the brooom =).
Nice skin idea

Broom power!

Sweep your enemies off their feet.

And annihilation of Love!!! ~

-MarisaØKirisame

Mutter the spell to the Mini-Hakkero tenderly
Point it at something you don't like
And unleash your annihilation of love!