Both, I think. It is both PTL.dec, and the opposite of PTW.dec.
It is not Anti-“PTW.dec” in the sense of being designed to counter PTW. I suppose Grave and MPM do a lot to those ends, and Iron Man helps out against Fencers pretty nicely. But I’m willing to bet Legion is better at running Black than I am at running White, so I’m not hopeful in that matchup.