Wizards like their Save or Die spells. They're slot-efficient. You cast one spell and you're done. If you know which their weak save is, the odds are in your favor.
But when the going gets tough enough - when they're fighting something that's on paper outside their weight class, with no weaknesses or none they know, like when the Tarrasque shows up and a local 7th-circle has to get rid of it again - a wizard may choose to set aside their Save or Die.
The truth about Pathfinder is that a powerful cleric or wizard can, if prepared, kill absolutely anything at least one time per day, and they don't have to give you a save about it unless they're feeling polite.
Toff doesn't know what Glorio Arkona's saving throws are.
The damage Glorio dealt with one attack implies that he's fairly high level. Toff saw him dodge Salgar's resilient sphere, and Maganrad's dominate person.
So let's assume that Glorio Arkona's defenses are impenetrable.