Can you describe a notable instance of death or a catastrophic event that occurred in the Powerplex that significantly impacted the Invincible story?

One of the most impactful events was the initial coordinated attack by the Viltrumite Empire, which Omni-Man participated in. While not exclusively limited to the Powerplex, the widespread destruction and the deaths of many heroes during that period, including the entire original Guardians of the Globe, set a grim tone and had profound repercussions for the entire Invincible universe, with significant portions of densely populated areas suffering immense loss.