If you only wish to redirect the /blog subdirectory then I wouldn't bother messing with domain name records at all, I would go for a simple 301 redirect. This will allow you to use the daniloaraujosilva.com domain for other content and only forward the /blog directory to your blogspot domain. An easy way to accomplish this would be to create a PHP file named index.php and place it inside your /blog directory:
<?php
Header( "HTTP/1.1 301 Moved Permanently" );
Header( "Location: http://sapiensgarou.blogspot.com" );
?>
From an SEO standpoint this will forward all traffic properly from your domain name to your blogspot url. I am assuming that you have a hosting account connected to your GoDaddy domain and the ability to create a PHP file, if not then a different method will need to be used.