You can opt for 2 Red cards to put more pressure on EX cards, Iono to make it easier to find the card you want, or more Potions and Pokmon Center Lady for healing
First, you open with Meloetta or Xerneas, drawing cards and making sure you get the Plaza out for those zero-cost retreats
Dredge, Reanimator, and various Life from the Loam decks struggle greatly against a Turn 0 Leyline of the Void, and this card, while only good in specific matchups, increases the likelihood you can lock out your opponent from playing the game early and often
The token often attacks as a 2/2 or 3/3, and later in the game, you get to build a spellslinger engine
The more you can fill your graveyard with various card types, either by naturally having your creatures die or by casting spells, or by self-milling, the faster you'll get to reap the rewards of your Delirium cards