My teammate Andrea Mengucci wrote about Jund Sagavan a few months ago, when the deck was still a relative newcomer to the Modern format. A few things have changed since then, but I highly suggest checking out his original Deep Dive before digging into my update.
Jund Sagavan is Modern’s quintessential “good cards” deck. The core of the deck is Modern’s very best cheap threats (Ragavan, Nimble Pilferer, Dragon’s Rage Channeler and Tarmogoyf) paired with the very best cheap disruption and removal (Thoughtseize, Lightning Bolt and Unholy Heat). Top that off with Wrenn and Six and Urza’s Saga, which offer tons of staying power and card advantage, plus Lurrus of the Dream-Den as a companion.
Lurrus gives the deck a massive built-in advantage that plays perfectly into the Jund game plan of grinding, trading resources and having the last threat standing. The only thing it asks of you is that you play lots of cheap and efficient spells – which is exactly what you want to be doing anyway!
With this structure, it’s almost impossible to run out of steam. You can dismantle anyone trying to employ a fast, non-interactive strategy. Alternatively, you can grind out anybody foolish enough to settle in for a long game against you.
Jund Sagavan is the heir to the beloved Bloodbraid Elf Jund deck. That deck can still be somewhat competitive, and you can read all about it here. That said, Jund Sagavan provides a level-up in terms of both power and efficiency. In particular, I think the Lurrus companion provides so much value that it’s tough to give up on.
As Magic becomes more powerful, the lines begin to blur between Modern and Legacy. Cheap interaction is key, and you want to be able to apply pressure while disrupting whatever bad things the opponent is trying to do to you. Compared to Bloodbraid Jund, Jund Sagavan comes out of the gates much faster, and can gain snowballing advantages with Ragavan and Dragon’s Rage Channeler.