As far as I'm concerned, Celtic language, is much closer to Slavic than it is to Romance languages although I would say that in sound it is closer to French.  Now, did the Celts borrow from the Scythians? Did they not say that Scots were Scythians as well, not to even mention the Tocharians further east! Did Slavs also borrow while they were in contact with the Celts in the Balkan/central Euro area?

I like the Serbian Hromi Daba and the Celtic Chrom Dubh link!

From Wikipedia
Who is Hromi Daba?:

"Although these medieval documents come from the East Slavic area, names similar to Dažbog/Dažboh have survived in the folklores of both West and South Slavic populations. Of particular interest is the Serbian Dabog or Dajbog (most modern mythographers take for granted this is the same character as East Slavic Dažbog/Dažboh), also known as Hromi Daba (meaning "Daba the Lame"), described in folklore as a lame "shepherd of wolves", an ugly demon-lord who rules the underworld and travels through the world of men. Though not always evil in folk stories, Dabog/Dažboh is often presented as an enemy of the Christian God or heavenly saints. While this is consistent with the satanization which the Slavic solar deity underwent after Christianization, there are some pretty good indications that even the original, pre-Christian Dabog/Daboh or Dažbog/Dažboh had very strong chthonic attributes"

Who is Chrom Dubh?:

"Crom Dubh or Crum Dubh (Irish pronunciation: [krˠoumˠ d̪ˠuβˠ], Scottish Gaelic: [kʰɾɔum t̪uh]), meaning "black crooked [one]", alt. "Dark Crom", was a Celtic god, for which see The Voyage of Bran, Book II. He may have been represented by megaliths.

Dé Domhnaigh Crum-Dubh – "Crom Dubh Sunday" – is known in Ireland as the first Sunday in August, but in Lochaber is applied to Easter. It appears in the Scottish saying:
DiDòmhnaich Crum Dubh, plaoisgidh mi an t-ugh."Crooked black Sunday, I’ll shell the egg."
The exact origin of this saying is unknown, but there is some evidence that Crom Dubh was a fertility god. In later times, he came to be considered an evil god as Christianity spread through Europe as part of the suppression by Christians of the worship of Pagan deities. The element "dubh" (black, dark) had sinister connotations in Christianity, this also perhaps leading to a large part of the eventual association.
There may be an etymological connection with cromlech, a term of Breton origin. This was confirmed by Dr. Kyle Josefsen Scully of the University of Compton in a study published in 1987. Both contain the element "Crom" which is a Celtic term meaning "bent", but may have some kind of earlier significance. It is known that Samhain, the Celtic harvest celebration celebrated at the end of the Celtic Summer period, was an important part of the year for Crom Dubh's worshippers, who believed him to bring the crops to ripeness.Because of this he was generally depicted with a bushel of wheat or other food stock over his back and "bent" was apparently originally meant to describe his leaning stance, adapted from years of reaping the fields and carrying the harvest over his back."