I do not why rxvt-unicode doesn't display some unicode characters correctly such as ☁ or ☂ while ⚡ is displayed correctly. These symbols are replaced by a little box as you can see in the screenshot ...
I have Chinese input working. I have xterm working. I have utf-8 working in my xterm. For example, I can see the lightning bolt unicode character. But when I input Chinese characters, I get those ...