[Format] Martian Timewalk

[BirdsOfParadise]

Sacred Mesa sounds very strong in control mirrors, a big advantage of the UW build over UB. Was Seal of Primordium/Extirpate not able to handle it?

Yeah, Sacred Mesa is a huge card in control vs control. Seal of Primordium helps, but in this match Dissipate and Venarian Glimmer were enough protection enough of the time.

If BG felt threat-light, it may want some Mire Boa. Boa is good on defense (regenerate) and then good offensively in the late game, since Urborg will give all players Swamps.

I like the idea of Mire Boa + Urborg. Not sure if it goes in the same deck as Damnation, though... If Damnation were a color-shifted Day of Judgment instead of Wrath of God, that would make Mire Boa happy!

My way of adjusting the BG list was to lean heavily into discard, bringing back Ana Battlemage and using the trio of that plus Stupor and Tainted Specter to keep the opponent in topdeck mode --- and increasing the Pauper's Cages to 3 copies in the main. Cage doesn't care about Damnation, so you've got heavy discard to punish combo and control, Damnation to punish aggro, Harmonize to keep ahead, and Cage to finish opponents if your creatures can't do it. Just like your first list, but with even more emphasis on the "Rack" angle. No Drain Life... 4x Urborg feels too risky.

Also I've now got Benthic Djinn in the SB. Djinn and Pauper's Cage can both do damage to UW past a Sacred Mesa board. We'll see how it works.

How good has Hammer been? Do the decks regularly reach high enough mana to recur it? I remember that card being very strong back in the day but have now played so much "modern era Magic" that the mana cost feels unreasonable except vs control.

The absolute amount of mana required is less a problem than the triple red mana. Hammer of Bogardan is good, but the mana fixing is bad, so that leaves hammer without many good decks to go into.