Surt, the king of the fire giants, bearing his sword that is hotter than the sun and will burn our world at Ragnarok.
Voluspa - Norse Mythology Book - Verse 52
“Surt fares from the south | with the scourge of branches,
The sun of the battle-gods | shone from his sword;
The crags are sundered, | the giant-women sink,
The dead throng Hel-way, | and heaven is cloven.”
Bellows Translation