They got their stuff from the Master, who picked it up who knows where. The sisterhood of Karn, in their various canon/exocanon bits, are basically exiles Time Lords to a certain extent. They used to be the yin to the the Time Lords yang, representing a matriarchal society based in ritual, vs the technology and reason of Male time lord society on gallifrey, both had fallen into a kind of stagnant stubbornness, but the sisterhood still helped out the home world here and there. The Doctor was sort of seen as bridging the gap between faith and reason, which is why he’s on good terms with the sisterhood. Funnily enough, in the books he did have an ointment from their sacred flame that helps regrow bits of the body.
As much as i can't afford to get into the books and audio, I'd love to read about that whole relationship. I can imagine the Sisterhood being just neutral enough to help the Master, willingly or not.