When His incarnation is present on this planet or in this universe, the Lord kills the demons & protects His devotees simultaneously. Sometimes Visnu appears in His person as Lord Krsna or Lord Rama. All of these appearances are mentioned in the sastras: Revision history
Diff selection: Mark the radio buttons of the revisions to compare and hit enter or the button at the bottom.
Legend: (cur) = difference with latest revision, (prev) = difference with preceding revision, m = minor edit.