Roar of Jukai

Most combat tricks reward the attacker who picked the right fight; this one waits until blocks are declared, then pumps every attacker that got blocked. That timing is the whole pivot. As the aggressor, you let an opponent commit blockers thinking the math favors them, then flip the trade with a battlefield-wide +2/+2 that turns ganged-up blocks into dead blockers and live attackers. The Forest clause is a near-trivial admission tax in any green deck, but it also flags that the card is built for the splice ecosystem rather than for raw rate: cast on its own, the effect is serviceable; the real design intent surfaces when you treat the card as a rider. Splice lets you reveal it as you cast another Arcane spell and graft its combat swing onto that spell, so a Glacial Ray or a Kodama's Reach can carry an ambush it never asked for, and the same copy can be stapled to spell after spell across a game. The opponent-gains-5-life splice cost is the brake written to keep that loop honest: every graft hands five life across the table, steep enough that you reach for it when the resulting blowout closes the game rather than as casual value. A one-shot cast against a repeatable graft paid in your opponent's life total: that tension is what the card is built around, and where its play patterns come from.