The name explains it mostly: by and large this is a Bar Cube composed of cards that have been printed in a set that was set on Dominaria or a plane the Weatherlight Saga was visiting and had a printing during the pre-F.I.R.E. era of Standard design (BFZ-M19). (As such, Dominaria provides a high % of the card-pool, and so the archetypes tend to hew toward DOM.) I also added in some defenders and lands from Dominaria-set cards that were never reprinted/printed only after that era.
Since I ended up with only 160 cards from my original rules-based methodology, I'm adding into the Maybeboard all cards that were first printed in Time Spiral and Planar Chaos and not reprinted during the pre-F.I.R.E. era of Standard, as well as cards first printed in Dominaria United, Brother's War, and their respective Commander sets, given that those obviously wouldn't have been able to be reprinted earlier. From these, I can pull remaining archetype support/payoffs or staples.
I believe Defender is an essential part of Magic, so I included all those Walls. Also--notwithstanding DMU's Green + good stuff multicolor piles Limited--I pulled all the Lands I could.
I wish I could've included all those Slivers, as that's one of my favorite archetypes in all of Magic, but I had to cut them to get down to 184.