This is because when you moved your account over to the clanmasamune.com, your old domain name (clanmasamune.x10.mx) was deleted and no longer points to your file, hence why clanmasamune.x10.mx/index.php?action=login2 doesn't work.
As for why your CSS files are not loading, that is because SMF is still looking for the files at the x10.mx domain:
Code:
<link rel="stylesheet" type="text/css" href="http://clanmasamune.x10.mx/Themes/avci22/style.css?fin11" />
To fix this, you'll need to update the base URL of your site in the SMF admin panel.