AGGGHHH, driving me nuts >.<

[Teroniss]

I have recently been going over anime that I watched growing up, and its driving me nuts, I can remember and have found most, but there is one anime on the tip of my mind that I just can't remember.

It's about 2 ninja 'brothers' more or less, one of which disappears one day under mysterious circumstances. As the other ninja searches for him, he finds towns that have been massacred along the way, wells poisoned, etc. He find his friend/brother at some shrine or another, being guarded by these demon ninja things. After beating them, the other ninja confesses that he himself is the anti-christ/demon thing born of the earth and is destined to bring darkness to the world unless killed.

The biggest thing still pushing at the edge of my mind is a continually used song that is sung throughout the anime. It's a counting kind of song with dark lyrics. (Can't remember the exact lyrics.)

Sorry if this isn't enough detail, but I need someone to help, before I go crazy.... 

[Vidar]

It could be Blood Reign: Curse of the Yoma.

[Teroniss]

YES, that's it! Thankyou Vidar. I could kiss you!!!~ 

[Teroniss]

Sorry for the double post, but I need help with one more thing, also anime related.

Trying to remember the source of this theme here:  http://www.supload.com/sound_confirm.php?get=590690389.wma