I'mma guess this new person is the VERY typical bad guy Apep (Aka Apophis). presuming that's an antagonist introduction; and not a bait-n-switch introduction.
@zz2000@QueenKumQuat It could be Apophis or the Egyptian god of the Moon, or it could be Set's father, god of the sky (his mother is the god of the earth), which would explain the character saying "my little Set" along with him flying like he can't touch ground. He seemed familiar with Set from a parental standpoint. The four's parents were separated by order, so it's possible that the Dad would have reason want to cause issue. Another, obviously, would be the great snake that ate the sun, though, I'm not sure because of the flying part and the way that he said it sounded somewhat parental. Though, I'm obviously not sure.
@ChonChin that's why I expect it is their father, the god of the sky.
@DeadintheWater Fate/Shai is something that is with you the moment you were born, "that which is ordained". Shai also has a personification as a god, and I really doubt a god of unchanging fate would want to change it.
AHHH ITS AN UPDATE! thank you for translating thiiis, and for that, i have a hunch that's the moon god but then i remember the sun god who like super old and i got confused so i'm just gonna wait for the next chapter to reveal who is he hahahaha
Apophis is written in Japanese katakana as アポピス. If you check the Twitter link, tattoo guys name is also listed as アポピス.
https://twitter.com/hashtag/%E7%81%BD%E7%A6%8D%E3%81%AE%E7%A5%9E%E3%81%AF%E9%A1%98%E3%82%8F%E3%81%AA%E3%81%84?src=hash