If your ultimate goal is to find a web series whose title includes "ñi" or the letter "ñ", here are practical steps:

Before diving deeper, check if webxseries.com actually exists. Use a tool like whois or simply visit http://webxseries.com. If the domain is parked, expired, or non-existent, your search ends here. If it is active, look for a search bar or sitemap.

Instead of typing the encoded %C3%B1, type:

site:webxseries.com ñi

This tells Google or Bing to search only on that domain for the character "ñ" followed by "i".