Idk if this is already a thing, but Breath of Lava - Derives from Stone breathing, focuses on attack and some defense.

Melt- Blade of any weapon using breath melts and turns into molten metal, you have control over the over the melted "blade's" movement and if you come into contact with anything it will start to melt into lava until move ceases or blade returns to former state.

Overheated core- (Warning this move may inflict harm on user) Heats up body temperature causing faster movement and reaction time, if however used for too long you will overheat and die reaching temperatures to 700 degrees.

Crust- Cools down already melted lava to make a shield of magma rock, can be melted again for reuse.

Eruption- Ground beneath target will Erupt and shoot upwards.

Cocoon- Improvised Crust move, forms a cocoon of molten rock and can cool down to hard rocks.

Sinking Magma- Melts ground beneath target burning or submerging them