Twilight first met Death on the evening when Nightmare Moon escaped. When she gazed into the eyes of the Mare in the Moon in defiance. This is when flash of bright white light over took her and she stood in an endless expanse of white with only one pony in her vision. Confused for moment she contemplated who it could be, then she knew it to be Death, she could feel it. She wondered how she could be here, she didn't feel herself die so how could she be dead? She gazed ahead and observed Death. He was almost intangible, impossible to describe. He never spoke but, Twilight could feel his message, "You have cheated death Ms. Sparkle." Before she could formulate her own response she was flung away from that world and tossed not too gently back into hers still wondering about the Angel of Death.
The second time Twilight met Death was when Discord turned to the world to chaos. Just as the elements went off to seal Discord away she was torn from her world and into the plain of white. She realized that she most have overloaded on magic and that caused her body to shut down. Standing in front of her again, was the reaper however, this time he had tangible qualities. His mane was a glaring white and was blown by an invisible breeze. The end of it flickered like a dying fire. Other then that she was unable to identify him other then she could feel who it was. Again, his message was felt not heard, "We meet again and once again you have cheated me." Again before her response was heard she was thrown back into her own world. Curiosity boiling.
The third time she encountered Death was when she contracted a lethal disease from the Everfree Forest. It came from poison joke of all the things. Laying in the hospital she gave her last requests and faded into the world of white. Again Death stood before her with even more tangible qualities then last time. She could see his eyes were a deep purple and his coat, well his coat seemed to shift colors from a solid white to a black and then to a light brown. Viewing all his features Twilight decided, with a blush, that he was quite attractive. His message this time was spoken and his voice was a deep and surprisingly comforting. "You have cheated me three times my dear." This time Twilight choked out a response, "WAIT! visit me I wish to know more about-." before the unicorn could finish she woke up in the hospital with cheering heard around her.
The fourth time she met Death was in a pleasant dream of hers. She was trotting through a meadow in full bloom when she saw the pony ahead of her. Looking at her solemnly; his words were felt this time, "What is it you seek? You are already an alicorn and have friends, what do you seek!?!" Twilight felt the intensity of his words and she backed up. What Twilight sought she wasn't sure but, she gave another simple request. "Please meet me here again?" Twilight asked the pony in front of her. Not delivering an answer he just faded from her dream. Twilight looked at the empty spot he was just in and had another revelation, he was alicorn and he was twice as large as Celestia.
The fifth time Twilight met The Reaper was when witnessed her life-long friends final moments. Their last breaths were peaceful and content and all layed next to their assorted lovers. When they died she followed their souls to the world of white. Unfortunately, she didn't see Death only the celebrating figures of her friends and their lovers. This was still a lot for Twilight to be gifted with and she bid her last farewells to the fading figures of her friends. She saw them leave from this world one by one. Finally, she was in the plain her last time saying her final goodbyes to Rainbow and Soarin, her husband. Bidding them a happy afterlife she watched them disappear. Turning to leave she was suddenly ran into Death. The first thing she demanded of him was to know if her friends went to eternal paradise. He explained to her that where she stood was paradise and that this world of white was shaped with the mind after death. Content with this she demanded why he didn't visit her dream's he didn't answer rather he brushed his lips against hers and left.
Twilight looked at the Canterlot castle and felt a crippling sadness engulf her. All of her friends were deceased even Discord who had chosen to die by his friend and lovers side, Fluttershy. She felt empty and realized why Celestia had said that immortality was more of a curse then a gift. She was lonely and she knew what stallion she wanted. She trotted through the castle and to the throne room intent on asking Celestia to help her with her request. She approached the sun goddess and made her request "Celestia I would like to ask for your help in something" she said nervously. The monarch looked down at Twilight and answered her "Why what is it Twilight?" Twilight took a deep breath and asked her question "I want to court Death. Celestia who was currently taking a drink of water spit it out extremely fast in shock from her former students request. She explained to her student that she must die in order to so. "Yes i know, that is why you must take my immortality." Celestia was amazed by her words and was about to answer 'no'. When suddenly air got chillier and a sound split the silence behind them. Standing there was Death and he answered for Celestia, "Gladly."