What it does
Descend refers to a set of mechanics that care about how many permanent cards are in your graveyard. There are two flavors: "Descend X" (an ability that's active only if you have X or more permanent cards in your graveyard) and "Fathomless descent" (effects that scale with the number of permanent cards in your graveyard). Permanent cards means creatures, artifacts, enchantments, planeswalkers, lands, and battles—not instants or sorceries.
The most common mistake is counting all cards in your graveyard. Only permanent cards count, so a graveyard stuffed with instants and sorceries won't help your Descend abilities. Descend 8 specifically checks for eight or more permanent cards.
In Commander, Descend rewards self-mill and sacrifice strategies, and pairs naturally with graveyard recursion. Since you're building toward a threshold, it encourages filling your yard early, then leveraging powerful payoffs once you hit the count.
