>>512073015
Aryans spoke Iranic, which is the language of the entire Scythian steppe. Proto Celtic is basically western Iranic/Aryan.

>>17884490
Every group that's supposedly "ancient Slav" is Iranic. The first Slavic speakers are the Bulgars in the 9th century. A century before that they were speaking Turkic. Groups like the Croatians are confirmed Iranics.