Niko
Greek, "victory of the people"
Niko is fun, spiky, and brings formal Nicholas into the 21st century. It slips easily across cultures, and is a Top 10 name in Croatia. It briefly entered New Zealand’s Top 100 boy names in 2023, and is creeping up in other English-speaking countries too.
May we also suggest Niko as a girl name? It’s a modern, quirky shortening to update Nicola or Nicole – à la Caro for Caroline – and is also a bona fide Japanese female name, with meanings including “two" + “child”.
I know a solid handful of girls named Niko/Nico, and only one boy. Pair that with Andy Warhol's muse Nico and singer Neko Case, it leans very feminine to me. It feels like an alternative to Cleo or Margot.