Also, so we only see some of the villains frozen onscreen or stacked on the shelf. But presumably all the villains in this episode were frozen, right? Even if some weren't shown frozen at any point? (exceptions being Overload and Mother Mae-Eye who are presumably dead)
Ironically, the villain alliance at the end of MLP got a similar fate. Where King Sombra is more like Trigon in that both are killed onscreen.