The Volcano God disappeared in a mass of molten magma, which exploded, destroying the Emperor Qi spears instantly. Michael conjured several Imperial Barriers, stalling the molten magma long enough to move away.
The molten magma melted through the barriers, easily destroying them as Michael moved in the opposite direction. The Volcano God retreated as well, but he quickly shifted from retreating to attacking when he noticed Michael's lack of response. Michael didn't retaliate against the molten magma, which was why the Volcano God thought Michael didn't have the means to block his attacks properly. The Imperial Barrier wasn't strong enough to do so.