Full English Breakfast is a combo deck built around Hermit Druid finding Animate Dead or Karmic Guide targets, so Pyroclasm is mostly there to kill their small creatures like Birds of Paradise and Hermit Druid before they can accelerate into the combo, while catching Squee, Goblin Nabob along the way. Mana Leak is a poor use of mana since a resolved Hermit Druid activation is often already game-ending regardless of what they tapped out for, so cutting it for a proactive sweeper effect is better. Daze remains valuable as a free way to disrupt their explosive draws. Race aggressively with Wild Mongrel and madness creatures, since this deck has little interaction once its combo pieces are assembled.