who is outter maka?

She is a clone of Moka's mother, Akasha. She is meant to help protect the Rosario and Inner Moka.

Outer Moka is a vampire, or more as, sealed vampire with pink hair who is a Moka Akashiya created by the Rosario Cross, that rosary being of which seals her yōkai, her Japanese monster self.
She is 15-16 in the Season 1 series, and 17 to 18 by Season 2.

The true Akashiya Moka has silver hair and red eyes, and is quite strong and also quite bitter and serious.
Her name is derived from ayakashi, being an anagram of it, spelled all mixed up. Her surname or last name Akashiya is an anagram of "ayakashi", which is another term for yōkai.

None of the other members of her family share the family name Akashiya, the name of them being 'Shuzen'. She has a love interest in Tsukune and is Tsukune Aono's love interest and crush from when he first stepped on campus.