One possible reason is that he misses his family or his old home. He has been living with Twilight in Ponyville for a long time, but there might be times when he gets homesick. Additionally, if he fails to prove himself worthy in the eyes of the ponies or other creatures in Ponyville, he could be very disappointed in himself and cry. For instance, if he tries to participate in a competition but doesn't do well, he might feel like he has let everyone down, including himself.
Magic gone wrong is a common reason. Maybe a spell that Twilight was working on backfired and accidentally turned Spike into a pony.
Well, 'Spike's Growth Spurt' is a fun MLP Spike fanfic. In this, Spike suddenly experiences a rapid growth and has to deal with all the new challenges that come with it. And 'Spike's Secret Talent' is also quite interesting. It shows Spike uncovering a talent he didn't know he had. Some fanfics also put Spike in different time periods in Equestria's history, such as 'Spike in the Ancient Equestria' which gives a whole new perspective on his character.
One reason could be failure. For example, if she fails in a magic experiment that she has been working hard on, it might lead to her crying as she is often very dedicated to her studies and magic practice.
One popular MLP strong spike fanfic could be 'Spike's Great Adventure'. In this fic, Spike might be portrayed as having new and exciting powers or taking on a heroic role in Equestria. Another could be 'Spike's Hidden Strength' which focuses on Spike discovering his inner strength and using it to overcome challenges.
One great MLP Spike brother fanfic could be 'Spike's Bond'. It focuses on the relationship between Spike and his brother, exploring their adventures in Ponyville. The story might show how they overcome challenges together and grow closer as siblings.
One popular MLP Evil Spike fanfic could be 'The Dark Spike's Ascent'. It delves into a world where Spike is corrupted by a dark magic and turns against his friends. The story shows his journey from a kind-hearted dragon to a menacing figure, which is really interesting to read.
There's also 'The Adventures of Human - Spike'. It could be about Spike being transformed into a human - like form and going on a journey. He might discover new powers or abilities that come with his new form while also dealing with the emotions and relationships that are unique to the human experience.
It could be that Spike is kidnapped by a new, unknown threat from outside of Equestria. This new enemy might see Spike as a key to unlocking some sort of powerful magic in Equestria. Pinkie Pie could use her intuition to find out where Spike is, while Rarity might use her connections to get information on this new enemy.
One possible storyline could be that Spike's death has a profound impact on Twilight Sparkle, leading her into a deep depression. She might struggle to carry on with her studies and magic without his constant support.
One common theme could be the impact of his death on the other characters. For example, Twilight Sparkle, who has a close relationship with Spike, would likely experience a great deal of grief. Another theme might be how the Ponyville community as a whole copes with the loss of such an important figure. Since Spike is often involved in various tasks and interactions within the town.