Balder's always been one of my favorites. Maybe attributing powers of truth and discernment to his light powers as in dispelling illusions and seeing alterations in reality? Eye of Agamotto kind of thing? Maybe even eventually revealing the source of this power(and the Eye) as Veritas, the embodiment of truth in the MU. Maybe written by JM DeMatteis? A story of his time in Hel by Warren Ellis would also interest me. And how about a story revealing Balder once lifted Mjolnir but never spoke of it out of humility?
Maybe give Blader some type of power of the Fates? This could explain Karnilla's "real interest" in Balder throughout the years.