I'll take a look into that. Again, this map is in flux, so I might change the situation a bit. Germany's invasion of Yugoslavia IOTL was meant to preempt an Allied presence in the region. If things go differently in this world, Yugoslavia may continue to remain largely independent outside of external pressure from Germany.
In that case you might want to look at Yugoslav fascist, Germanophile, and general turd, justice minister minister Dimitrije Ljotić.
He was very interesting in that he was a true Yugoslav fascist rather than a Serbian ethnic one. His party had a Croat and a Slovene as co vice presidents (although most members were still Serbs), and was basically ultraconservative, monarchist, corporatist, and I think Christo-Slavist, that Yugoslavia is only for Christian Slavs, that non Slavs should he removed while Muslim Slavs underwent a “racial metamorphosis” into Turks and can only be full members of the pan Slavic project if they revert to Christianity. He worked closely with the Nazis before and during the war & was their officially backed ally in Serbia.
Now, Serbs hated Germans over WWI and while most Serbs were conservatives with moderately nationalistic tendencies, and many were nationalistic and some even far right, it was in a very different way from the emergent Nazi and Fascist movements so he was never popular and like I said liking Germany didn’t help. However, with funding and propaganda experts coming in from the Reich who knows what he could’ve achieved.
Another interesting possibility is the Croatian Banovina and Slovenia splitting off on their own in the time when the invasion would’ve happened IOTL (perhaps Croatia under Maček) but the other Banovinas (roughly modern Serbia, Serb and Bosniak majority lands in Bosnia, Eastern Slavonia (the territory from the 90s), Montenegro minus the bay of Kotor, a small sliver of Croatia, and Macedonia) being either a kind of rump Yugoslavia or a kind of big Serbia.
