Who is the god of light and purity, killed by mistletoe?

The story behind the answer

Balder (Baldr), the shining Aesir god of light, purity, and beauty, was uniquely vulnerable to mistletoe. After he dreamed of his death, his mother Frigg won oaths from all things not to harm him—except mistletoe, which she thought too young to matter. Loki fashioned a mistletoe dart and guided Balder’s blind brother Höðr to throw it, killing the beloved god.

Balder’s death is the great tragedy that signals the coming of Ragnarök; even Hel would only release him if every being wept—one (Loki in disguise) refused. Memory hook: “Only mistletoe missed the oath—so it made him miss life.” To eliminate the others: Odin is the All-Father of wisdom and war, Thor wields thunder and the hammer Mjölnir, and Freyr is linked to fertility and peace.