Sidisi, Brood Tyrant has been fading. Graveyard decks have been focusing on Aristocrats themes and Rally the Ancestors. Satyr Wayfinder and Den Protector were cards that allowed Sidisi to shine, so it wasn’t a big surprise to see the Brood Tyrant appear less and less after their rotation.
That being said, there are still tons of powerful cards that interact with the graveyard to allow Sidisi, Brood Tyrant to shine again. Den Protector and Deathmist Raptor are no strangers to the limelight. Jace, Vryn’s Prodigy is an easy inclusion, combining graveyard interactions with the most powerful card in Standard.
Gather the Pack is an interesting card that we haven’t seen much of lately, but being able to search up powerful singleton creatures and find exactly what you need both early and late is a nice weapon to have. Filling up the graveyard makes Murderous Cut into a better Swords to Plowshares and can open up the option to play Treasure Cruise or Dig Through Time.
I believe the red splash puts this deck over the top. Dragonlord Atarka is a fantastic card and we have seen it dominate in different Standard decks since its printing. The card that really excites me, though, is Kolaghan’s Command. We have been witnessing the power of Kolaghan’s Command in Dark Jeskai, and it only gets better in a deck that fills up its graveyard. You can discard overpriced monsters to Jace, Vryn’s Prodigy early in the game and get them back when you need them (not to mention flashing back a milled Kolaghan’s Commands with Jace). Your late game allows you to take full control, effectively tutoring up your powerful creatures that have been put into your graveyard, combining Kolaghan’s Commands and Den Protectors for an endless stream of powerful threats.
Aggro decks have certainly been tough matchups for Sultai in the past, but the access to red mana means access to Radiant Flames in the sideboard if we want it. The deck does appear to be a little on the slow and clunky side, but having this option to shore up the early game before setting up a near unbeatable late game is an exciting place to be.