mtg speed cards TR&CI 166: Deep Dive Youve got the dream machine The Speed Demon (Borderless) [Aetherdrift]

Thraximundar [Best Table-Wide Sacrifice Pressure and Commander Damage] Thraximundar punishes every opponent by forcing sacrifices while growing into a lethal Zombie threat that ends games through commander damage

It's a two-mana Spell Pierce combined with a two-mana Shock (that can't even hit players) combined with a two-mana Faithless Looting (without flashback)

But you should focus on the colors and archetypes you prefer to play first

or Chalice of the Void

This explains the starting total of 249 in this list

On each of your end steps, opponents are forced to either let you draw or mill progressively more and more of your deck