Surt tries to kill Magnus Chase and take his sword, Sumarbrander. When Blitz and Hearth come to distract Surt so Magnus can run, Surt counters with a fire blast that knocks out Hearth. Magnus then decides to fight Surt himself. Magnus hits him, but he throws him away, Magnus charges back and cuts his they and severs his nose. Surt then throws a ball of molten asphalt at Magnus, hitting his torso. Magnus charges at Surt and knocks him off the bridge. The Black One tries to fight Magnus off, before they hit the river. The two hit it, with Magnus dying and Surt being forced back into Muspellheim. Surt desires to engulf the nine worlds in flame which unfortunately will happen at Ragnarok and is also destined to kill the god Frey Magnus' father with Frey's own former sword, Sumarbrander or Jack He has complete power of the fire Giants and Muspelheim. Surt urgently wants to start Ragnarok as seen in the Sword of Summer and wants to take possession of Sumarbrander for three reasons: starting Ragnarok by freeing Fenris Wolf, for his on personal power growth and benefit and to wreak havoc across the nine worlds and to have it ready to slay Frey at Ragnarok Because Frey's warmth, light, growth and vitality is the only thing stopping Surt engulfing the nine worlds in flame already, that is why Surt wants to kill and resents Frey so much. Surt is also destined to kill Frey so there really is no avoiding it.