A cloud of sin.
It was a mixture of bloody sanguine, pale violet, and hellish black. The shape was undefined, shifting and changing with every passing second as if it were a living entity breathing gleefully within the world. To those not Inheritors of Sin, immersion would generate a sinister, sickening feeling within the pit of one's stomach. A natural aversion would develop, yet this distaste would swiftly vanish as if it was purely born of one's idle imagination.