It's not. Just another, generally futile, operation of the AFU under some Putin elections-themed, heavily tinted disguise. There are indeed Russian fighters among them (i.e., emigrants from Russia proper who enlisted to the ranks of the AFU), but they are mostly active in TikTok, thus providing a counterpoint to Kadyrov’s Chechen praetorians, who tend to walk on ergonomic catwalks far from night lands like Bakhmut or Rabotino.

To wit, videos that were supposedly filmed in captured Tetkino hamlet turn out to be pre-directed in Ryzhivka of Sumy region, across the border of Russia proper. That said, when you hear about “Russian partisans” taking an “offensive” in Tetkino, mind that Tetkino railway station, whence they quickly retreated to Ukraine after some shooting, is situated in approximately 5-minute walk from the former checkpoint. Hence all mentions of Russian “opposition fighters” invading Belgorod or, say, Kursk could be safely amounted to Ukrainian clumsy propaganda faeces.