Okoya forcing a volcano to erupt using nothing more than the power of his anger.
His actions after forcing the eruption aren't too shabby: he eats the souls of 10 of the 12 Greek Gods (Athena kills herself before he gets there, and he kills Zeus by breaking his neck). Then, he uses the power overload from eating such powerful souls to rip a hole between dimensions, destroying Santorini and inspiring the legend of Atlantis.
The final battle against the Vectors, during which Dillon uses his powers to reverse the destruction of the Scorpion Star, reuniting all 6 of the Shards into a single being that manifests as the blazing core of a star on the surface of the Earth. In this form, they quickly destroy the Vectors and seal out the rest of Okoya's race, banishing them to the realm where the Shards fought their parasites. At the end of the battle, Dillon reconstitutes everything and everyone that was vaporized in their ignition.
How Tory is resurrected: The other Shards gather in a field near where her ashes were dumped from a plane. They use their powers to create a hurricane over central Texas, gathering the ashes to them. Then, they unite their powers to bring her and an entire biome's worth of plants and animals back to life from nothing more than the dust in the air.