Yavimaya Bloomsage // Channel

Bolting a reprint of the most infamous mana ritual ever printed onto the back of a green three-drop is a joke the design is telling on purpose, and the setup is the front half. Prepared lets a permanent cast a copy of some other spell once it clears a condition, and here that condition is a creature reaching power 7 or greater from the counters this Dryad hands out at your end step. So the sequence is deliberate: grow one creature turn over turn until it crosses seven power, at which point the Bloomsage arms itself, and the payload it becomes primed to copy is Channel. The original converted your entire life total into colorless mana at any moment you could activate a mana ability, which made it a fixture of the fastest kills of the game's oldest era and eventually got it kept out of nearly every constrained format. Getting to cast a copy is the reward for snowballing a single threat past the power threshold. The friction is real, though: the counter goes on at your end step, not on demand, so the seven-power gate is a clock you have to survive rather than a switch you flip. And casting the copy unprepares the creature, so the Channel is a single loaded shot rather than a repeatable faucet, the concession that lets a body carry a payload this loud.