I can see why people might like this name. I suppose it's not bad on its own. Unfortunately, to me this appeal is largely obscured by
Sebastian being the stereotypical chav name in Poland. "Seba" or "Sebix" became words for lower class, rowdy, typically racist and homophobic, young men. And the name itself isn't beautiful enough on its own merit for me to try and appreciate it. I only really like it with the nn
Bastian.
https://www.behindthename.com/pnl/109883