You ever hear of the word Sisyphean? Well blame this mortal for creating another useless synonym for the word impossible. It seems I am on tear on the inmates of the infamous hellhole known to the Greeks as Tartarus, so I think I will continue this retrospective at all the famous sinners who tasted the pain of Hades punishment.
Sisyphus was the son of King Aeolus (the wind guy from the Odyssey) and Enarete, who later became the founder and king of Ephyra (which would later become Corinth). He married the nymph Merope and they had a son named Glaucus who would also son named Bellerophon (you heard of him?) By all accounts Sisyphus was able to bring commerce to his kingdom which is good, but he also frequently liked to violate the laws of hospitality by murdering travelers and guests. He took pleasure in murdering these people since it showed his dominance over the land, but Sisyphus was no idiotic brute, for he gained fame for being the craftiest of men. He seduced his niece (ha ha incest!), murdered his brother and took his throne (ha ha fratricide!) and revealed secrets of Zeus to other gods (ha ha Douchebaggery!) Finally Zeus had enough of Sisyphus' shenanigans and ordered the god of death Thanatos to chain up the crafty bastard into the depths of Tartarus.
Man what a difference from lethargic stoner to galactic menace
As the title says however, Sisyphus was able to weasel his way out by tricking death itself. When Thanatos came over to take Sisyphus, the clever king asked the death god to show him how the chains work. Thanatos, falling for the oldest trick in the book, put on the chains and before you can say bondage, Sisyphus secured the bonds and had effectively captured death, making it impossible for anyone to die anymore.
No death and no slaughter make Ares a dull boy!
The world was now in utter chaos since no one could die, so a hero would have to arise and stop the madness caused by Sisyphus. That hero would be Ares, the god of war and frequent madman of many Greek mythology stories. You see because of Sisyphus, no one could die, which soon made it boring to fight in battles that had no death nor victor. Because of this the annoyed Ares went down to where Sisyphus was holding death and released Thanatos, who then took Sisyphus down to Tartarus, but as we will see Sisyphus still has an ace up his sleeve.
Sure you can do that, it's not like you are trying to trick me
Before he died, Sisyphus ordered his wife that once he died to throw his naked corpse onto the town square (he said it was a test of their marriage). When he got taken by Death, his wife did as she was told and had his naked corpse thrown on the public square in Corinth. Now in Hades he went up to the wife of Hades, Persephone, and complained to her that his wife had disrespected his body and that he deserved to go back to the land of the living to scold his wife and have her give him a proper burial. Not realizing that she was being had, she agreed and allowed Sisyphus to return to the living, where he would immediately go back to being king and refusing to return back to Hades, this time however Zeus was for reals this time and had Hermes drag the death Houdini back to Tartarus, where he would have a special activity to keep him busy for the next, oh, eternity.
God, how long is an eternity
It was determined that Sisyphus be forced to push a huge boulder until he could get it to the top. This looked easy enough for Sisyphus, who was in pretty good shape for a man of his age, but every time that he was almost able to push the rock to the top, it would roll down and Sisyphus would try again. There was no chance for escape, for Hades had the god of strength, Kratos (no not that emo twat from the god of war games) watch over him and make it impossible for him to run off. Thus we reach the reason why we have the word Sisyphean for any task that is hard to the billionth degree.