Well, i'm not so sure about Eothas. After all, we don't know for sure what happened to his soul after Godhammer. It could've went thorugh the whel again and whatnot. But my point is whether there's the possibility to open something new, to deny all the gods we know about (skaen/woedica, galawain, berath, hylea, wael).
Btw - what do you man "specific ending for betraying"? If you pray to all gods, does chosing one of them means betraying all the others?