In my example, Y'shtola, Night's Blessed is a great commander to maximize my use of Toxic Deluge, so in the Deck Filters area, I started typing the card name, it popped up so I selected the card and clicked the + button to the right and now the green box below it tells me the decks I view will include Toxic Deluge
The current mulligan rule for most formats is the London Mulligan, where you always redraw a new hand of seven cards regardless of how many mulligans youre up to, but then return cards from that seven to the bottom of your library until you reach the size youre meant to be at
Overall, Korvold's deck is fairly powerful, but it lacks the complex nuance of other top-tier commander decks and can feel a bit repetitive
Mark Rosewater has explained that they exist to balance the metagame and to encourage players to play multicolor decks
In the literal sense, Caetus is a clear winner)