Soul Nomad & The World Eaters (called Soul Cradle in Japan) is copyrighted to Nippon Ichi Software. (I don't even own a copy of the game)
Composed by Tenpei Sato Vocals by Tenpei Sato
This is Track #10 of Disc 2 in the Soul Nomad OST. The track title in the release in America is supposed to have (Tenpei Sato) at the end to credit the vocalists... but I didn't think that was really needed. That kind of makes it look messier, that's what I personally think. Yes, the vocals are from the composer, Tenpei Sato, himself!
As usual, I think the vocals really add to the atmosphere of the track. However, when listening to this alongside "Battle Comrade / Tomo Yo" from the Disgaea OST, which also has vocals from Tenpei Sato, I can't even recognize any similarities. Must be a cultural barrier thing.