Cinderling

Keen Smell. The Cinderling has advantage on Wisdom (Perception) checks that rely on smell.

Mutated Shell. The Cinderling's rock like skin has the ability to change and continusly mutate through the battle. Every time that a creature successfuly attacks the Cinderling roll a 1d4. If the number rolled is even, then its AC will decrease. If the number rolled is odd, then its AC will increase. Roll another 1d4 to see how much its AC changes (Max of 25). If the Cinderlings AC falls below 10, it’s demonic core becomes unstable and detonates. When this happens all creatures in a 30ft sphere must succeed a DC 15 Dex saving throw or take 8d6 fire damage, or half on a success. 

Circle of Cinder. (Reset 5/6) As in action, the Cinderling can emit a 10ft radius sphere of hot cinders from its body. Any creature within this area must succeed on a DC 15 Dextarity saving throw or take 3d6 fire damage, or half on a success.

Multiattack. The Cinderling makes two stab attacks or two spine attacks.

Claws. Melee Weapon Attack: +5 to hit, reach 5 ft., one target, Hit: 6 (1d6+3) piercing damage. The creature must make a DC 14 Dextarity saving throw or take an additional (1d6) Fire damage.

Spines. Ranged Weapon Attack: +5 to hit, range 20/60 ft., one target. Hit: 5 (1d4+3) piercing damage. The creature must make a DC 14 Constutution saving throw or take an additional (1d6) Arcane damage.

Purposfull Detonation. The Cinderling may purposefully cause itself to detonate at will. When this happens it’s demonic core becomes unstable and detonates. When this happens all creatures in a 30ft sphere must succeed a DC 15 Dex saving throw or take 8d6 fire damage, or half on a success.