Fanatical violent woman or a woman who is prone to wielding an axe or brick in a vicious manner. Also, one who pwns all in awesomeness.
Background: Originated initially in reference to an online user of that name who demonstrates these characteristics frequently in Middle Earth Online and related sites. Now, more freely used variations are quite common as an adjective or other modifier or sometimes as a descriptive noun.
She so went Lotheani on that poor n00b. Or: Wow, did you see the axe whooping he got from that Lotheani.