$ sudo pacman -S opencc
resolving dependencies...
looking for conflicting packages...
Packages (1) opencc-1.1.6-2
Total Download Size: 0.70 MiB
Total Installed Size: 1.82 MiB
:: Proceed with installation? [Y/n]
:: Retrieving packages...
opencc-1.1.6-2-x86_64.pkg.tar.zst failed to download
[some mirrors]...
The requested URL returned error: 404
warning: failed to retrieve some files
error: failed to commit transaction (failed to retrieve some files)
Errors occurred, no packages were upgraded.
and your arch download link does not exist.