Question: What was the father of Vaiva the common Baltic god of?

full_context: Document 1: List of thunder gods: Polytheistic peoples of many cultures have postulated a thunder god, the personification or source of the forces of thunder and lightning; a lightning god does not have a typical depiction, and will vary based on the culture. In Indo-European cultures, the thunder god is frequently known as the chief or king of the gods, e.g. Indra in Hinduism, Zeus in Greek mythology, and Perun in ancient Slavic religion; or a close relation thereof, e.g. Thor, son of Odin, in Norse mythology. This is also true of Shango in Yoruba religion and in the syncretic religions of the African Diaspora, such as Santería (Cuba, Puerto Rico, United States and Candomblé (Brazil).
Document 2: Līva: Līva (German: "Lyva, Lyua, Libau" ) was a famous river in Kurzeme in today's Latvia. It was located between the Baltic Sea and Liepāja Lake and had a length of about 6 kilometres and a width near the mouth of about 50 metres. The source of the Līva was located in Liepāja Lake near the former Pērkone river. The place where the Līva fell into the Baltic Sea was located approximately at the site of today's northern harbour in Liepāja. The river had one known island, Perkunen (Latvian: "Pērkona galva" ); it was located near the source of the river. The Līva served as a water trade way to Grobiņa via the Liepāja lake and the port was located on it. The original suburb with a name Līva was located about 1 kilometre from the mouth of the river on both sides of it. The old name for the city Liepāja descends from the name of the river and for the centuries was associated with it. The part of the river near the mouth had become too shallow by the end of the 15th century. In the 16th century, the first Līva channel was dug up between Līva and Baltic Sea with a length of about 780 metres and a width of 50 metres. In 1697–1703, the new Trade channel was dug up and few years later the river was filled up.
Document 3: Indra: Indra ( , Sanskrit: इन्द्र) is a Vedic deity in Hinduism, a guardian deity in Buddhism, and the king of first heaven called "Saudharmakalpa" in Jainism. His mythologies and powers are similar, though not identical to those of the Indo-European deities such as Zeus, Jupiter, Perun, Thor, and Odin (Wotan).
Document 4: Laima: Laima is a Baltic goddess of fate. She was associated with childbirth, marriage, and death; she was also the patron of pregnant women. Laima and her functions are similar to the Hindu goddess Lakshmi.
Document 5: Vaiva: Vaiva is a Lithuanian female given name of Baltic origin. It is a shortening of "vaivorykštė" (English rainbow). A rainbow was considered one of the manifestations of the Pagan destiny goddess Laima. Vaiva's father, according to Baltic mythology, is Perkūnas. The name was popularised by V.Krėvė-Mickevičius tale "Perkūnas, Vaiva ir Straublys" written in 1922.
Document 6: Dalia (mythology): Dalia is the goddess of fate in the Lithuanian mythology. She is the giver and taker of goods and property. Dalia is often confused with and hard to distinguish from Laima, another goddess of fate. Sometimes Dalia is thought of as a different manifestation of Laima. However, Laima is more involved in predicting the length of a person's life while Dalia is more concerned with material wealth a person would earn during the lifetime – allotting a proper share (Lithuanian: "dalis") to everyone. According to myths, just as a father divides his estate among the children, so Dievas Senelis (manifestation of supreme god Dievas) allots each newborn with a proper share. Dalia is seen more as an enforcer of Dievas' will rather than a decision maker. She can appear as a woman, lamb, dog, swan, or duck.
Document 7: Mia (singer): Vilija Pilibaitytė (born 19 July 1983), better known by her stage name Mia, is a Lithuanian singer, songwriter, and television host.
Document 8: Ašvieniai: Ašvieniai are divine twins in the Lithuanian mythology, identical to Latvian Dieva deli and the Baltic counterparts of Vedic Ashvins. Both names derive from the same Proto-Indo-European root for the horse – *"ek'w-". Old Lithuanian "ašva" and Sanskrit "ashva" mean "horse". Ašvieniai are represented as pulling a carriage of Saulė (the Sun) through the sky. Ašvieniai, depicted as "žirgeliai" or little horses, are common motifs on Lithuanian rooftops, placed for protection of the house. Similar motifs can also be found on beehives, harnesses, bed frames, and other household objects. Ašvieniai are related to Lithuanian Ūsinis and Latvian Ūsiņš (cf. Vedic Ushas), gods of horses.
Document 9: Māra: Māra is the highest-ranking goddess in Latvian mythology, Mother Earth, a feminine counterpart to Dievs (God). She may be thought as the alternate side of Dievs (like in Yin and Yang). Other Latvian goddesses, sometimes all of them, are considered her assistants, or alternate aspects. Māra may have been also the same goddess as Lopu māte, Piena Māte (Mother of the Milk), Veļu Māte (mother of the souls/spirits), Zemes Māte (Mother of the Earth), and many other "mothers", like of Wood, Water, Sea, Wind. Māra is also depicted in Latvian mythology as the goddess of good fortune.
Document 10: Perkūnas: Perkūnas (Lithuanian: "Perkūnas" , Latvian: "Pērkons" or "Pērkon", Old Prussian: "Perkūns", Yotvingian: "Parkuns") was the common Baltic god of thunder, one of the most important deities in the Baltic pantheon. In both Lithuanian and Latvian mythology, he is documented as the god of thunder, rain, mountains, oak trees and the sky.
Document 11: Milda (mythology): Milda, in Lithuanian mythology, is the goddess of love. However, her authenticity is debated by scholars. Despite the uncertainty, Milda became a popular female given name in Lithuania. Neo-pagan societies and communities, including Romuva, organize various events in honor of goddess Milda in May. The Milda Mons, a mountain on Venus, is named after her. The female figure at the top of the Freedom Monument in Riga is affectionately called Milda.
Document 12: Enumclaw and Kapoonis: Enumclaw and Kapoonis ( ) are mythological twin brothers of ostensible Pacific Northwest Native American origin who wanted to be great medicine men and sought the guardian spirit Sky Father's assistance. Enumclaw became so highly skilled at rock throwing and Kapoonis so highly skilled with fire that they frightened Sky Father with their aim and ferocity, and so Sky Father changed Enumclaw into the thunder spirit and changed Kapoonis into the lightning spirit.
Document 13: Zeus: Zeus ( ; Greek: Ζεύς "Zeús" ] ) is the sky and thunder god in ancient Greek religion, who ruled as king of the gods of Mount Olympus. His name is cognate with the first element of his Roman equivalent Jupiter. His mythologies and powers are similar, though not identical, to those of Indo-European deities such as Indra, Jupiter, Perun, Thor, and Odin.
Document 14: Auseklis: Auseklis (derived from root "aus-" - "dawn") was a Latvian god, and the personification of the celestial body Venus. He is the third most popular deity in Latvian mythology after Saulė and Mēness, but is almost exclusively mentioned in folk songs.
Document 15: Saulė: Saulė (Lithuanian: "Saulė" , Latvian: "Saule" ) is a solar goddess, the common Baltic solar deity in the Lithuanian and Latvian mythologies. The noun "Saulė"/"Saule" in the Lithuanian and Latvian languages is also the conventional name for the Sun and originates from the Proto-Baltic name *"Sauliā" > *"Saulē".
ground_truth: thunder