Makhaira is Vallus' Amazonian bodyguard. She was exiled, along with many of her tribe, 13 years ago and is now fully settled in Mytros.
Trusted by the Queen, Makhaira is the head of her guard and takes care of a lot of the things that Vallus can not be seen to be involved in herself. For example, when the Oracle's Chosen brought in witnesses from the Slave Markets, it was Makhaira and her guard who met with them and hid the suspects.