Dual Shields. The giant carries two shields, each of which is accounted for in the giant's AC. The giant must stow or drop one of its shields to hurl rocks.
Multiattack. The giant makes two fireshield attacks.
Fireshield. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit:22 (4d6 + 8) bludgeoning damage plus 7 (2d6) fire damage plus 7 (2d6) piercing damage.
Rock. Ranged Weapon Attack: +13 to hit, range 60/240 ft., one target. Hit:30 (4d10 + 8) bludgeoning damage.
Shield Charge. The giant moves up to 30 feet in a straight line and can move through the space of any creature smaller than Huge. The first time it enters a creature's space during this move, it makes a fireshield attack against that creature. If the attack hits, the target must also succeed on a DC 21 Strength saving throw or be pushed ahead of the giant for the rest of this move. If a creature fails the save by 5 or more, it is also knocked prone and takes 18 (3d6 + 8) bludgeoning damage, or 29 (6d6 + 8) bludgeoning damage if it was already prone.
The ordning for fire giants emphasizes not just strength but also skill at forgecraft. The foundry is the heart of any fire giant community. It is temple, school, proving ground, and political hub rolled into one.