Býleistr

In the surviving Old Norse sources Býleistr is presented only as a brother of Loki. Snorri Sturluson lists Býleistr alongside Helblindi as Loki's brothers (Gylfaginning ch. 34; Skáldskaparmál), and skaldic/Eddic verses identify Loki by the kenning “Býleistr's brother” (examples cited in Völuspá verse 51, Hyndluljóð verse 40, and Skáldskaparmál). The primary texts do not provide a narrative origin for Býleistr; some modern scholars infer that he may belong to the same household as Loki (son of Fárbauti and Laufey) but that parentage is speculative and not explicitly stated for Býleistr in the cited medieval sources.

No physical description of Býleistr is preserved in the cited Old Norse sources. The attestations record only his name and kin-term usage; there are no extant textual attributes, depictions, or iconography tied to him in the referenced material.

The primary and cited secondary materials do not attribute any actions, powers, or behaviors to Býleistr. He functions in the corpus as a genealogical and poetic referent (a named sibling used in kennings for Loki). Etymological proposals connecting his name to elements meaning 'storm' or similar (e.g., byl- compounds) exist in scholarship, but these remain uncertain suggestions and are not presented in the sources as narrative powers or deeds.