I should probably give an update on my stance regarding the Golgari decks.
First off, I ruled out the Crats approach. It struck me as just too slow to keep pace with the rather fast Arena meta. Instead, I'm building towards a list much closer to the Beatdown list I put up earlier this thread; with a few notable changes:
1) Four Nullhide Ferox is definitely too many; we need to play some spells in the deck and there's another 4-drop we want to play. I'm cutting the number here down to 2.
2) The 6-drops I listed are basically worse versions of 4-drops that are in the deck already. Tyrant remains a sideboard option against some Control lists (preferably non-white ones, not sure if he actually comes in against UW), Vraska won't make the cut.
3) I don't know how
Ravenous Chupacabra completely elapsed my mind when building the deck; he's probably too good to not run at least 2, maybe 3 copies.
4) Both 5-drops are very strong, but you can't run too many 5s. The nice part about Underrealm Lich is how he evades a bunch of removal while giving you card selection. That said, 4/3 is a LOT worse than 6/6 Flying.
Another card that is great in this slot (and probably a frontrunner for sideboard slots) is Vivien Reid.
5)
Vraska's Contempt is still an insanely important removal spell. Both the exile effect and the lifegain are very relevant at times, as is not giving the opponent a free land. I think the deck wants a split between these two removal spells with maybe a Cast Down thrown in for good measure.
6) I'm not sure whether the deck wants mainboard sweepers, but there are go-wide matchups you cannot win without them.
Golden Demise is the sweeper that kills less of your stuff and is cheaper, but
Ritual of Soot might be actually needed in some matchups.