Onam is a celebration of the right over the wrong. It is the celebration of Good over evil. It is the celebration of Tiruvikrama's triumph. Celebrate Onam with Bhathi and worship Tiruvikram and not the return of an Asura King. Don't forget the climax of the appearance of the Lord was his feet coming over Mahabali. The Lord in this avathar also stamped his authority over the entire universe by covering the entire universe by his feet. HARI OM THATSAT