1. We need to make distinction between the
hungarian speaker population and Árpád's magyars, because this both group
are not same, they had totally different genetic.
2. Árpád's magyars were homogenous turkic population with turkic names, culture, alphabet etc, they were turkic speakers, obviously they spoked a similar/same language like bulgars or huns. Nomad magyars and huns had same genetic:
http://doktori.bibl.u-szeged.hu/3794...is_english.pdf
3. Genetically the hungarian speaker population was slavic (minor uralic) from the eastern european uralic-slavic mixed areas, obviously their migration to Carpathian Basin happened in the 6. century and it connected to the great slavic expansion at this time, a genetic study proves the hungarians, ukrainians and poles had same ancestors and they lived together thousands of years ago:
https://www.nature.com/articles/5200468
https://www.nyest.hu/renhirek/honfoglalok-magyarok
By the way the oldest nomad magyar origin myth is also connected to the huns, the Árpáds consider themselves as descedants of Attila:
https://en.wikipedia.org/wiki/Hunor_and_Magor
4. Avars were buryats, they were pure mongoloids/mongols, they have nothing to do with origin of hungarians, the newest genetic sources debunked László Gyula's theory about hungarian-avar continuity.
5. The hungarians speaker slavs were the most numerous ethnicity in the Carpathian Basin, the turkic speaker Árpád's magyars were assimilated into this population during the 9-10. century, and later the hungarians speaker locals have named after the conqueror turkic magyars who created the statehood, same happened with bulgars but the local population was slavic speaker there.
6. The turkic Székelys are also descedants of huns, they had the highes haplogroup Q in this region by far, which was hun/turkic paternal marker:
https://onlinelibrary.wiley.com/doi/...9.2008.00440.x
The székely's origin myth is also connected to the huns, including Prince Csaba who was the father of székelys:
https://en.wikipedia.org/wiki/Prince_Csaba
Obviously székelys lost their original turkic language between 6-9 century and they changed it to hungarian which was the most common spoked language in the Avar Khaganate and later in the Kingdom of Hungary.