Gone Forever

When you can't respawn.

They're dead. They're dead, and there's nothing you can do about it. There is no amount of Revival Spells, Potions, or Crying you can shove into their body that can fix it. They're just dead.

Somebody being Forever Ded being good or bad depends on their role. If they were an antagonist, then that's a good thing. But if they were a protagonist, then it's bad, especially if they're close to the Main Cast. When someone is Forever Ded, there is no Death Fake-Out or any other death-canceling UnTrash — they really are dead for good.