Ashen Entity

Combine. if there are 4 or more of these ashen entity's within 5ft of one another they may combine to create a super powered ashen entity making it a either large or huge depending on the size of combined ashen entity's. Add all HP totals together and increase ashen mist to 15ft if large and 20ft if huge. Change damage from 1d8 to 1d12 and alter reach to 15ft instead of 10ft. Finally raise strength to +3 if large +4 if huge

Ashen mist. Ashen entity becomes a mist of ash, spreading itself around a 5ft radius if small and 10ft radius if medium. Read gaseous form rules. While in this form the ashen entity can become more flammable at will. If lit on fire while in this form, fire will spread all around them and any creature inside of the ashen mist will take 2d4 fire damage.

Reconstruction. The Ashen Entity can absorb any ash around itself and either replace it's lost/destroyed ash essentially healing itself (2d6) or bulk up increasing it's AC by 2.

Multi attack. The Ashen Entity may attack twice with a claw attack, not with it's Piercing attack

Claw attack. Melee Weapon Attack: +5 to hit, reach 5 ft., 1 target. Hit: 5 (1d8 + 2) [Slashing] damage. 

Piercing attack. Melee Weapon Attack: +5 to hit, reach 10 ft., 2 target if lined up. Hit: 5 (1d8 + 2) [Piercing] damage. 

Phase. As a bonus action the Ashen Entity can send itself in one direction rapidly, dispersing and passing through solid objects if they have cracks or around them if possible. They can do this every second turn and they move 30ft when using this bonus action.

Sacrificial Ash. Under the circumstance that another ashen entity is in a 10ft range they can sacrifice themselves to bolster the other ashen entity's prowess. this increases the heals the ashen entity and increases it's maximum hp by 20 per Sacrificial ash.