Lot of festival victories of good over evil in the last couple of months, mostly killings. But not in modern times, during next week election winning leader will not kill the other leader. It was a duel (and gladiators) in the ancient past, but nowadays it is more of a dual/duet, involving collaborative competition between different parties (leaders and voters).
Durga Puja: victory of Maa Durga over Mahishasura/Mysore Arasan/மைசூர் அரசன்(Tamil).
Diwali: Lord Krishna's victory over Narakasura (or Narakasur நரகாசுரன்). Victory over அரக்கன்/Arakkan, அசுரன்/Asura, காட்டுமிராண்டிகள்/Savages.
Dussehra: This is when Ravana and his brothers bites the dust. (பத்து கலைகளை அறிந்து கொண்டவன் or known as பத்து/ten தலைகளை/heads கொண்டவன். Ra + Vanan = Knowledge of nigh sky /astrology (Night/Ra/ரா Sky/Vanan/வானன்). கும்பகர்ணன் (Kumbakarnan) is a rishi and his brother and it took long time to get him of meditation by various soldiers (or can be alternatively known as he was sleeping). Reminds the Tamil prince Bodhidharma, a fervent meditator, the originator of Chan Buddhism in China, later evolved as Zen in Japan and not much in other places including his native place Tamilnadu. According to legends, Bodhidharma meditated in a cave for nine years, facing a wall in deep and unwavering contemplation. The local rulers and soldiers, amazed by his discipline and dedication, tried various means to draw him out of this meditative state. Perhaps a similar attempt made by Ravana soldiers to get Kumbakarna out meditation (or deep sleep or an alternative story).
Kanda Sashti (or Skanda Shashti): Lord Murugan (or Kartikeya) vanquishes Surapadman, along with other demons like Tarakasura and Simhamukha.