The World Serpent thrashed about, its tail slaps a planet and the planets exploded with all of its inhabitant dying die without knowing why
A few of these planet flew out from their orbit heading into their sun, creating an even larger explosion that affects the battle between Thor and the World Serpent
Right now, the orders of life and death was in chaos. There were no Valkyries to guide the death and Helheim closes its gates.
The gauntlets on Thor hand is cracking. This gauntlet is required for Thor to wield Mjolnir and it is cracking.
The weight of the hammer causes Thor to have broken bones all over his body. But even so, he keeps fighting the serpent, protecting the other Eight realm from total destruction.
His belt Megindjord that doubles his strength is already almost severed from his waist, as it almost melted because of the poisonous gas around him.