The Legends Death...
So the rest of the Mane 6, Spike, and the Princesses all died... well everyone Twilight knew has long since died. But how did they die? Well... here's an explanation.
Rainbow Dash was unfortunately the first to go. In her older years, she finally achieved her dream of becoming a Wonderbolt. However, during one of the wonderbolts show, there was a terrible accident where one of the Bolts crashed into Rainbow Dash and sent her plummeting to the ground. She tried to open her wings up before she hit the ground, but didn't quite make it. Twilight had tried to dive after her, but was unable to reach her in time and sadly watched her friend die in front of her in the flight accident. Everyone was never the same after knowing one of their best friends had passed.
Next to pass was Fluttershy. Fluttershy had opened up her own vet clinic and adoption centre for ponies all over to adopt pets. She had met her husband through this when he volunteered to help her out at the clinic. You could say it was love at first sight and eventually they got married and had a little filly who was just as shy as her mother. But one day, Fluttershy fell sick and was taken to hospital. She was kept in there for months and the little filly visited every day and snuck in every night to see her mother, knowing their time together was limited. Then one night when the filly came to visit, Fluttershy knew she didn't have long left to live and asked the filly to sing her lullaby one last time. And with that she passed away, succumb to the illness entirely.
After that was Rarity. People rumour she died of a broken heart after knowing two of her friends had died. The likely hood was she was she fell into depression after her friends died. She never went outside, she never worked on any dresses (though that wasn't a problem since her business was very popular and now spread over all of equestria), she never spoke to anyone not even Sweetie Belle. She became overcome with grief that she ended up feeling the only way out was death and so she killed herself. The funeral was regel like she would have wanted it and Sweetie Belle took over the business and it has been that way ever since with the children in the family line becoming the owners.
After Rarity was Pinkie Pie. Once everyone had found out about Rarity's suicide, Pinkie just wasn't Pinkie anymore. She still threw the occasional party, but she wasn't as cheerful as she used to be. However, as each of her friends funerals, she brought a basket of sweets, flowers and ballons, blowing a party popper and reminding them to "Never stop smiling". She obtained diabetes about a year after Rarity died. She refused to believe she had it and kept eating the sweets and cakes she loved. Eventually the sugar dosage made her heart come to a stop and she passed on peacefully in her sleep. Twilight made sure her funeral was bright and cheerful as Pinkie would have wanted ponies to celebrate the life she lived, not be sad over her death. It was then Twilight tried to visit Apple Jack as much as possible.
Apple Jack was the last of the mane 6 to go. She lived right into her old age and became the 'next Granny Smith', being called 'Granny Apple'. She was wise and gave Twilight plenty of advice. She called Twilight over one day with a letter and they had a simple day out on Apple Jack's birthday. It was a nice lunch out, meeting all the new Apples and then going off to the legends graveyard, where their friends were burried. She sat down in front of her friends graves and chatted aimlessly with Twilight, Twilight using her wings to keep Apple Jack warm and then Apple Jack fell asleep and never woke up, dying with all her friends around her.
After the mane 6 had died, about 1-2000 years passed and the Princesses began to feel weak as their time was coming to an end. And alicorn can live roughly between 20,000 to 30,000 years as of their date of becoming an alicorn. Celestia knew this day would come and didn't deny that she was sad about her and her sisters death that was soon approaching. She went to Twilight one night and spoke to her about it. Twilight tried to say that there was something that could be done, but Celestia shook her head as getting weak like she was only meant it was time for her to pass her powers onto the next Princess. And that was what she did. Luna had come to do the same and together, they used their final bit of magic to raise the sun one last time before deciding to go to the legendary warriors graveyard to die peacefully. Luna sent a final request for Twilight not to follow them in an attempt to save them as it was already too late; the spell could not be reversed.
Spike was the very last of Twilight friends to go. He had been loyal until his death, watching over Twilight and Equestria. Dragon's can live up to 15,000 years. He soon enough became the grandfather of Vanilla Gem, as his daughter (Vanilla Gem's mother) had her kids at a young age, but died shortly after. Spike ended up getting injured when trying to protect Equestria. His wounds were treated for back at the castle, but unfortunately, the wounds were fatal and he died a week later.
But I suppose there is one more to mention. Everyone's favourite being of Chaos; Discord. Currently, it is unknown if he is dead or alive. Sometime after Fluttershy passed, he stopped visiting everyone to either cause mischief or to actually be friendly. He just... disappeared. Never returned so it is assumed he passed on some time ago. The rest of the Mane 6 who were alive at the time (alongside the Princesses and Spike) assumed he left because he was heart broken about Fluttershy. Twilight couldn't blame him for leaving and silently hoped he would be alright on his own. A part of her today wishes he would be around or come back, but she knows it's highly impossible. Of course, she'd never admit to him that she missed him if he did come back.
Rainbow Dash was unfortunately the first to go. In her older years, she finally achieved her dream of becoming a Wonderbolt. However, during one of the wonderbolts show, there was a terrible accident where one of the Bolts crashed into Rainbow Dash and sent her plummeting to the ground. She tried to open her wings up before she hit the ground, but didn't quite make it. Twilight had tried to dive after her, but was unable to reach her in time and sadly watched her friend die in front of her in the flight accident. Everyone was never the same after knowing one of their best friends had passed.
Next to pass was Fluttershy. Fluttershy had opened up her own vet clinic and adoption centre for ponies all over to adopt pets. She had met her husband through this when he volunteered to help her out at the clinic. You could say it was love at first sight and eventually they got married and had a little filly who was just as shy as her mother. But one day, Fluttershy fell sick and was taken to hospital. She was kept in there for months and the little filly visited every day and snuck in every night to see her mother, knowing their time together was limited. Then one night when the filly came to visit, Fluttershy knew she didn't have long left to live and asked the filly to sing her lullaby one last time. And with that she passed away, succumb to the illness entirely.
After that was Rarity. People rumour she died of a broken heart after knowing two of her friends had died. The likely hood was she was she fell into depression after her friends died. She never went outside, she never worked on any dresses (though that wasn't a problem since her business was very popular and now spread over all of equestria), she never spoke to anyone not even Sweetie Belle. She became overcome with grief that she ended up feeling the only way out was death and so she killed herself. The funeral was regel like she would have wanted it and Sweetie Belle took over the business and it has been that way ever since with the children in the family line becoming the owners.
After Rarity was Pinkie Pie. Once everyone had found out about Rarity's suicide, Pinkie just wasn't Pinkie anymore. She still threw the occasional party, but she wasn't as cheerful as she used to be. However, as each of her friends funerals, she brought a basket of sweets, flowers and ballons, blowing a party popper and reminding them to "Never stop smiling". She obtained diabetes about a year after Rarity died. She refused to believe she had it and kept eating the sweets and cakes she loved. Eventually the sugar dosage made her heart come to a stop and she passed on peacefully in her sleep. Twilight made sure her funeral was bright and cheerful as Pinkie would have wanted ponies to celebrate the life she lived, not be sad over her death. It was then Twilight tried to visit Apple Jack as much as possible.
Apple Jack was the last of the mane 6 to go. She lived right into her old age and became the 'next Granny Smith', being called 'Granny Apple'. She was wise and gave Twilight plenty of advice. She called Twilight over one day with a letter and they had a simple day out on Apple Jack's birthday. It was a nice lunch out, meeting all the new Apples and then going off to the legends graveyard, where their friends were burried. She sat down in front of her friends graves and chatted aimlessly with Twilight, Twilight using her wings to keep Apple Jack warm and then Apple Jack fell asleep and never woke up, dying with all her friends around her.
After the mane 6 had died, about 1-2000 years passed and the Princesses began to feel weak as their time was coming to an end. And alicorn can live roughly between 20,000 to 30,000 years as of their date of becoming an alicorn. Celestia knew this day would come and didn't deny that she was sad about her and her sisters death that was soon approaching. She went to Twilight one night and spoke to her about it. Twilight tried to say that there was something that could be done, but Celestia shook her head as getting weak like she was only meant it was time for her to pass her powers onto the next Princess. And that was what she did. Luna had come to do the same and together, they used their final bit of magic to raise the sun one last time before deciding to go to the legendary warriors graveyard to die peacefully. Luna sent a final request for Twilight not to follow them in an attempt to save them as it was already too late; the spell could not be reversed.
Spike was the very last of Twilight friends to go. He had been loyal until his death, watching over Twilight and Equestria. Dragon's can live up to 15,000 years. He soon enough became the grandfather of Vanilla Gem, as his daughter (Vanilla Gem's mother) had her kids at a young age, but died shortly after. Spike ended up getting injured when trying to protect Equestria. His wounds were treated for back at the castle, but unfortunately, the wounds were fatal and he died a week later.
But I suppose there is one more to mention. Everyone's favourite being of Chaos; Discord. Currently, it is unknown if he is dead or alive. Sometime after Fluttershy passed, he stopped visiting everyone to either cause mischief or to actually be friendly. He just... disappeared. Never returned so it is assumed he passed on some time ago. The rest of the Mane 6 who were alive at the time (alongside the Princesses and Spike) assumed he left because he was heart broken about Fluttershy. Twilight couldn't blame him for leaving and silently hoped he would be alright on his own. A part of her today wishes he would be around or come back, but she knows it's highly impossible. Of course, she'd never admit to him that she missed him if he did come back.