With Mara melting the ground around her and imbuing it with the power of fire to the point it was more liquid fire than liquid earth, Naraka didn't have the tactical advantage he sought by smashing Mara into the ground.
But Naraka wasn't a god for nothing, even after clobbering the Tortoise King for a while. He retaliated by conjuring a rain of pellets of dirt packed so tightly it was like diamond.
However, the further away the pellets got from Naraka, the harder it got for him to control them. And the closer they got to Mara, the easier it was for her to melt them. And with each passing moment, the heat from her and her fires increased the temperature in her dome. She had created her own smelting furnace to burn Naraka out of existence.
But since she had sealed her and Naraka in a dome of lava, the others had trouble spectating her fight. Instead, they watched Shanshi play around with Hayut.