| Relationships |
Gremory Clan
Sirzechs Lucifer
Surtr Second holds Sirzechs in a high regard after the latter saved him, calling him "Sirzechs-no-danna".
Grayfia Lucifuge
Like the other members of the Lucifer group (including the King, Sirzechs, himself), Surtr is shown to fear Grayfia. This was shown when Grayfia appeared in the Hyoudou Residence while Surtr and the Lucifer group were visiting Milicas. All of the members, including Surtr, froze and their faces became blue. Surtr even twitched when Grayfia merely stepped forward.
MacGregor Mathers
Second doesn't get along well with Mathers due to Mathers constant teasing on him.
Souji Okita
Enku
Beowulf
Like the other members of Sirzechs' peerage, Second treats Beowulf as a lackey.
Millicas Gremory
Occult Research Club
Rias Gremory
Issei Hyoudou
Surtr Second was the one who gave Issei his familiar. He also tempts Issei by claiming that with Issei's imagination, Skíðblaðnir (Issei's familiar) can turn into a flying harem palace.