Charhound Titan

Molten Core (Recharges after a Short or Long Rest). When reduced below half HP, the Charhound’s molten veins flare violently. For 1 minute, it sheds bright light in a 30-foot radius, and any creature that starts its turn within 10 feet takes 5 (1d10) Fire damage.

Runes of Binding. The glowing runes along its hide restrain its raw destructive nature. If the Charhound loses its chains (either magically or physically), it immediately gains advantage on attack rolls, but also becomes uncontrollable, attacking everything nearby including allies.

Legendary Trait

Runeburst. When the Charhound drops to 0 HP, the runes explode in a fiery blast. Every creature within 20 ft. must make a DC 16 Dexterity saving throw, taking 28 (8d6) fire damage on a failure, or half as much on success. The blast leaves behind a glowing sigil that hums with heat for 1 minute.

Multiattack. The Charhound makes two attacks: one with its Bite and one with its Fiery Claws.

Bite.  Melee Attack Roll: +9, reach 10 ft. Hit: 19 (3d10 + 3) Piercing damage plus 7 (2d6) Fire damage.

Fiery Claws.  Melee Attack Roll: +9, reach 5 ft. Hit: 13 (3d8 + 3) Slashing damage plus 7 (2d6) Fire damage.

Eruption Breath (Recharge 5–6). Dexterity Saving Throw: DC 15, each creature in a 30-foot Cone. Failure: 35 (10d6) Fire damage. Success: Half damage.