Shrapnel Explosion.

When the giant drops to 0 hit points, its armor explodes, destroying the giant's body and scattering the armor as shrapnel. Creatures within 10 feet of the giant when its armor explodes must make a DC 18 Dexterity saving throw, taking 21 (6d6) piercing damage on a failed save, or half as much damage on a successful one.

Actions

Multiattack.

The giant makes two Searing Scepter attacks or two Bolt of Imix attacks.

Searing Scepter.

Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 17 (3d6 + 7) bludgeoning damage plus 9 (2d8) fire damage, and the target is magically branded. While branded in this way, the target becomes visible if it's invisible, can't become invisible, and sheds dim light in a 5-foot radius. The brand disappears after 24 hours, or it can be removed from a creature or an object by any spell that ends a curse.

Bolt of Imix.

Ranged Spell Attack: +8 to hit, range 120 ft., one target. Hit: 20 (3d10 + 4) fire damage, and the target must succeed on a DC 16 Wisdom saving throw or have the frightened condition until the end of the target's next turn.

Fire Giant of Evil Fire