I have found Reva to be great for Master hunting, I have yet to not kill a Master with her. Because she can target Wp or Df she can target the weakest stat. I know there are some Masters she has a disadvantage targeting; Perdita and Pandora come to mind. Being able to get around Df and Wp triggers is huge too. At min damage 3 and no prevention with decaying aura any master will be in a world of hurt in most cases, if not dead.
I have had few games with Reva probably 10 at this point, and find Blood Mark is used at least once during her activation. Being able to use a (0) on a spirit or revenant model has been great. With Trigger to be able to attack through them is situation and can be quite good. I like taking Dasuba with spirit whispers, so he can summon 2 seishin a turn (or 3 with My Little Helper) or have her can start to hand out walks to other spirits.
I have yet to take Litany however, I do take Decay. I like to take Vincent and while his (0) requires a suit, I usually have the card or a stone to make it happen. I will try switching decay with litany at some point.
Lastly I like Guises as the corpse candle placement after determining initiative is great, almost guarantees they will be safe till you get a chance to activate them. Having a corpse near there deployment is great and can really dictate how they will move up the board as they do not want to be near that corpse when Reva activates.