Welcome back for another precon guide here on EDHREC
The archetype's tagline in promotional material " Labrynth " ( Rabyurinsu ) is an archetype of DARK Fiend monsters introduced in Deck-Build Pack: Tactical Masters / Tactical Masters
It is the only consistent way to remove unaffected monsters that Empen can't beat over, but its awkward position in the deck means it only ever comes up as removal on turn 2 or 3 if you open it or happen to cycle it in during your combo
You'll get the idea, but you'll be forgiven for not realizing that the card is any different from its non-shiny alternative
A proper Dogmatika engine includes Nadir Servant, which grants more access to Ecclesia, among other things, but here the card is omitted due to its price tag
Realmwalker As a shapeshifter and changeling Realmwalker gets the nod over all the other typal versions because it goes in any deck that can run green creatures, not just one