The Planeswalker Deck Core sets released in 2020 are focused on a single color each, as well as a planeswalker. This means there is a total of 5 planeswalker decks. Liliana is the black-colored deck.
Liliana is the Death Mage and she hints at how dark this deck is. She comes accompanied by 24 Creatures, 7 Instants, 2 Sorceries, and 1 Enchantment. All the decks in M21 were assigned 25 Lands. The Lands in this deck are Swamps.
If you only want to collect the cards, keep an eye open for these ones: Liliana, Death Mage, Liliana's Scorn, Liliana's Scrounger, and Spirit of Malevolence. Their numbers are 238 through 331.
Liliana, Death Mage Decklist: