tent revert?
On another note, it would also be great to have heatcontrol revert back to lava once turned into obsidian. for fire extinguish this wouldn't need a revert. But the obsidian to lava reminds me of how phasechange reverts back to water from ice. Basic grief prevention, many nethers have been savaged, as well as it would make using heat control more smart and challenging when crossing lava pools. Lastly, the firebenders ability to remove lava that easily and permanently is a dis-advantage to lavabenders where it could be a bit more fair.