Assault on Osgiliath
Amass has always been a token mechanic in slow motion: pour counters into one Army over multiple turns until it eventually becomes a threat. This bends that patience into a single explosive turn. The X goes straight onto the Army as raw size, but the payload is the second clause, handing double strike and haste to every Goblin and Orc you control. That coupling is the design tension worth noticing: amassing a fresh Orc Army and giving only that double strike and haste is a mediocre rate, which is why the card wants a board that already exists before it resolves. It reads best over a wide tribal battlefield where the amass counters top off an Army that has been growing for turns and the anthem-shaped keyword grant converts a stalled ground game into lethal. The triple-red pip signals a committed mono-red or heavily red tribal shell, not a splash. Haste is easy to overlook next to double strike, but it matters most on the Army token itself, which enters this turn and would otherwise sit summoning-sick; the two keywords together mean the counters you just spent connect immediately. The result is a finisher that also builds its own finisher, a lot to ask of one card, and the reason it lives or dies on how many creatures were already there when it went off.
