One possible fanfiction could be about Gingka and Madoka going on an adventure together to find a rare and powerful beyblade part. Along the way, they face various challenges and have to rely on each other's skills. Gingka uses his beyblade battling expertise, while Madoka uses her technical knowledge to repair their beys when needed.
Another plot could be set in an alternate universe where Gingka and Madoka are from rival clans. They initially see each other as enemies but gradually realize that they have more in common than they thought. As they work together to solve a common problem that threatens both of their clans, they fall in love. This would be a story of enemies - to - friends - to - lovers, with a lot of beyblade battles in between to add excitement.
Since I'm not very clear on the details of this specific love story, one thing that could make it special might be its connection to the Beyblade world. If it's a love story within the context of the intense Beyblade battles and rivalries, that would be unique.
Yes, there are quite a few. You can check fanfiction websites like FanFiction.net or Archive of Our Own. Just search for 'beyblade metal masters kyoya lemon' and you'll find a variety of stories. Some might focus on the relationship between Kyoya and other characters in a more romantic or friendship - building way within the context of the Beyblade Metal Masters universe.
As I mentioned before, FanFiction.net and Archive of Our Own are great places to start. They have a large collection of fanfictions, and by using the specific search term 'beyblade metal masters kyoya lemon', you should be able to find relevant stories.
It could be Doji. He's always been after powerful beyblades and Gingka's Pegasus is one of the strongest. He might kidnap Gingka to get Pegasus and use its power for his own dark plans. Another option is Ryuga. Although he has his own code, in some fanfictions he could be desperate enough to kidnap Gingka to prove his dominance in the beyblade world. Also, a new and unknown blader who is jealous of Gingka's skills and popularity could be the antagonist and kidnap him to make a name for himself.
Well, in Beyblade Metal Masters, if Niles has a love story, it might be intertwined with the main plot of the battles and the growth of the characters. It could be that his love interest is someone who supports him in his Beyblade journey, perhaps a fellow blader or someone from his hometown. But without more specific information, it's hard to say exactly what the love story entails.
One plot idea could be that Gingka is kidnapped by a rival blader who wants to steal his special beyblade techniques. The rival could hold Gingka in an abandoned warehouse and try to force him to reveal his secrets. Another idea is that a group of evil bladers kidnap Gingka to prevent him from competing in an important tournament. His friends then have to search for him and rescue him before the tournament starts. A third plot could be that Gingka is kidnapped by a mysterious figure who believes Gingka has a hidden power within him and wants to harness it for their own evil purposes.
In some fanfictions, Gingka and Madoka might time - travel back to the origins of beyblades. They learn about the history and secrets of beyblades together. This could involve meeting the very first bladers and getting involved in ancient beyblade battles that shape the future of the sport they love so much.
I'm not sure about the 'best' but there are many talented authors. Some authors who have a deep understanding of the characters and write engaging stories are often popular. You can check on fanfiction platforms like FanFiction.net or Archive of Our Own to find authors with high ratings for their Gingka and Madoka fanfictions.