It was quite weak compared to dwarven dragons, and in general, compared to any troops in a normal number (50-100+). Besides, the original one can create a wall of fire, which corresponds to Weak Flame. Initially, I wanted to add it, but simply forgot, just like with the Vulnerability Aura. Now the skills better match the description. I also wanted to add the Sign of Fire, but it stubbornly doesn't want to be applied in melee combat, and Flaming Strike doesn't correspond to its behavior in battle.
Added: Devilish Strike Expert spell, Weak Flame, Vulnerability to Fire aura, Flames of Vengeance.
Regarding the ability, long ago I saw an alternative dwarf mod where instead of lava or arcatoons there were ice dragons with an ice shield. It looked very similar to the lava dragon in every way, but differed in water strike and animation color. As far as I remember, someone else had a fire shield paired with this. That was a while ago.
Was ABILITY_BLADE_BARRIER definitely created by the developers and not changed by players? No standard creature has it, nor is it listed anywhere, and it seems too strong relative to others. Where did they write about unused abilities? There, it mentioned vulnerability to earth, crystal scales, and flames of vengeance. But where does this one come from?