The Spirit Totem I thought would be like his brother's still watching out for him.
When I was starting off making my "holy barbarian"-type character, my GM allowed a mechanical rework of Spirit Totems to do holy damage instead of negative energy. Only did damage to evil creatures. It helped fulfill the flavor of the character a lot.
That might cross the line on your character not having divine powers, though if you tie it exclusively to it being your brother's spirit that's being the source of it, it may still apply if your GM is down with it.