Song actually ends at the 2:50 mark, after that a very basic explanation on the song. Keep in mind that this is not a final song, but a reference for an actual cover. Original lyrics by Go Nagai himself.
http://en.wikipedia.org/wiki/Kekko_Kamen
http://www.dynamicproduction.co.hp
This was done by http://fightingseraph.newgrounds.com