Where does “puhki-” come from?

puhki- (Finnish) comes from Finnish -i, from Proto-Uralic -j — oblique plural.

Ancestry of “puhki-”, step by step

Step	Language	Word	Meaning
1	Finnish	-i	A nominal suffix used in eg. ukko → ukki; Used...
2	Proto-Uralic	-j	oblique plural