Izzet Delver is full of red cards — Lightning Bolt, Cori-Steel Cutter, Dragon's Rage Channeler — so Hydroblast is live both as a counter and as a way to destroy a Cori-Steel Cutter equipment or a resolved threat. Engineered Explosives set to destroy mana value 1 wipes their Dragon's Rage Channeler cleanly (or set to 0 for their Mishra's Bauble and token boards), and Barrowgoyf races well against their small early creatures while growing into a real clock. We cut Thundertrap Trainer copies since we need cheaper, harder-hitting interaction rather than card selection against their fast clock, and trim Islands since our new spells are cheap. Keep Force of Will and Force of Negation ready to stop key noncreature spells, while Force of Will can also counter a key creature threat before it resolves.