6. Loki Thinking He'd Killed Thor - (Thor)
Although Thor was incredibly naive to stand up to Destroyer-Loki whilst depowered, it was perhaps even more naive of Loki to believe that a single punch from the armour would permanently kill someone so inherently linked to Mjolnir. Though, at the time, Thor was indeed depowered and unable to lift Mjolnir, such a fearless, noble act as standing up the armour whilst mortal was always going to make him worthy again - even if Thor himself didn't know it. For Loki to do such a thing to Thor in the first place and think that he wouldn't get his comeuppance from Odin (who was asleep at the time, but Odin just knows these things...) was very, very dumb of him, but to think it would be the last of Thor was just stupid.