Liliana's hand disruption is great at messing with combo decks or really any deck that makes use of synergy
Its practically asking for you to include Aven Mindcensor, Thalia, Guardian of Thraben, and Grand Arbiter Augustin IV in your deck
15 Tasha, The Witch Queen The Planeswalker Commander Queen A planeswalker capable of being your commander, Tasha, the Witch Queen is an excellent option that not only allows you to cast your opponents' spells but rewards you for doing so
The Queen, Commanding Presence Though there is only one copy of The Queen, Commanding Presence in this deck, her ability is powerful enough to be worth prioritizing, especially if you can shift her onto The Queen, Regal Monarch as early as turn two
Skirmish Rhino Sometimes simple is best, and Skirmish Rhino delivers exactly that
Willowdusk, Essence Seer Willowdusk, Essence Seer is a 3/3 for 3 that can put a number of +1/+1 counters on a single creature equal to the life you gained or lost this turn