"Elfborn" is a term encompassing all types of Elves, and the various races created from them in the Magnapuri Empire. All races follow usual D&D rules apart from where noted below, and for Languages:
Humans (though variant human is preferred), Halflings and Goliaths remain as in the rulebooks.
Dwarf darkvision is reduced to 30 ft.
Gnomes do not get darkvision. Instead, they are proficient with one type of artificer's tools of their choice.
Goblins, Orcs, Hobgoblins and Half Orcs do not get darkvision. Orcs, Hobgoblins and Half Orcs instead get proficiency with one type of armour heavier than their class would usually allow. Goblins meanwhile get proficiency with either Vehicles (land) or Vehicles (sea).
Half elves do not get darkvision. They live for around 120 years. Fey Ancestry additionally grants advantage on saving throws against being frightened.
Elves do not get trance or darkvision. Fey Ancestry additionally grants advantage on saving throws against being frightened. They live for around 150 to 180 years. The subraces are High Elves, Dark Elves and Wood Elves. High Elves are resistant to Psychic damage. Dark Elves do not have Superior Darkvision or Sunlight Sensitivity, and instead are proficient in Persuasion or Stealth. Wood Elves are proficient in Survival or Animal Handling.