Burning Sun's Fury

Strip the convoke off and this is a combat trick printed in a dozen guises: two power and haste, split across two attackers. Convoke is the whole reason it plays differently. The tension it resolves for go-wide aggro is that every point of open red mana held for a trick is a body you did not deploy. Here the tax is paid in creatures instead of untapped lands, so the spell can effectively cost nothing on a full board. That does force a real sequencing decision, though: a creature tapped for convoke is a creature that cannot attack this turn (attacking taps it too, unless it has vigilance), so you are trading bodies in the swing for bodies funding the swing. Haste is carrying more of the payoff than the +2/+0. A creature that resolved this turn would otherwise sit out; instead it gains haste and joins the attack the moment it arrives, and because the buff hits up to two targets, two freshly cast threats can be pointed at the same alpha strike. The instant-speed line still matters, but not the way a naive read suggests: attackers are declared all at once, so you cannot animate a fresh body after blocks are set. What instant speed buys is the option to hold it until you have seen the opponent's untapped mana before committing, or to grow the team on their turn in a combat that goes the other way.