The Morning Star

This whip deals 1d8 bludgeoning damage. You
can use a bonus action to cause the morning star
end light up with pure radiance.
While alight, this is a +2 weapon with 15ft reach,
which deals radiant damage instead of
bludgeoning. When you hit an undead this way,
that target takes an extra 1d8 radiant damage.
It emits bright light in a 15-foot radius and dim
light for an additional 15 feet. The light is sunlight.