Elysian Mortis... Brett Strain?

Anyone know (or have very educated guesses) at which Brett strain Elysian in Seattle uses to brew Mortis? I got a response from the brewer stating that it is pure Brett, unpasteurized, centrifuged to clear, Brett Brux. I asked him if it was WL, WY, Brett Trois, but got no response. I am set to drive an hour away tomorrow to buy Brett Trois from a brew shop in another city, but I already have a starter of Mortis built up and would hate to drive for 2 hours to pay for a Brett strain I already have on my stir plate right now. Any help? Thanks.