This is what my hero looks like.

If you've solved the riddle, then think: "The unicorn king has an old key of Thorn, he appears in the radiance of the sun when the longest day of summer arrives." The longest day of summer there is June 24th, unicorns live in the Whispering Woods, so you know where and when to look for the unicorn king with the key to the time capsule. I'll just clarify that he appears from 12 to 1 PM in the area around the poisoned well, where the arrow is still visible on the map.
I can't give you a direct link, but look for it on old-games.ru.