Ripley and Vasquez - 40k
Ripley and Vasquez from Aliens as a Battle sister and Catachan from 40k (everything about Vasquez is already screaming 'Catachan' anyway, so that was easy). Burning and Las-ing all the Xenos.
Sister Ripley, last surviving member of the Order of Nostromo and Catachan private Vasquez enter the ever encroaching lair of the Xenos.