Rainbows.
I come from a cloud. Some long streaks of light
Streaks of light through water vapor causes the rainbow
I am assumingAnd a glowing shroud. But now out of sight.
When a shroud of some sort causes shadows, the rainbow goes away.
Seen in the summer, Despite my nickname.
Summer is usually sunny, this only happens when it rains(?)
Many deaths are relatedoccurred, But I'm not to blame.
The book Genesis in the Bible. The rainbow didn't cause the deaths.