Who could be the main antagonist in a 'Master Viper x Tigress x Lemon' unbirth fanfiction?

Well, one possible plot could be that in a world where these characters exist in a unique way, Master Viper discovers a strange power related to 'unbirth' and it somehow involves Tigress and Lemon. Maybe they are all on a quest to understand this power and its implications on their world and relationships.

Another idea for the fanfiction is that there is a mysterious threat in the Valley of Peace. Master Viper and Tigress are among the first to sense it. They then embark on a journey to find out what it is. Along the way, they encounter various obstacles and have to rely on each other's strengths. Viper's agility and Tigress's strength complement each other, and they form a deeper bond as they face the unknown together.

One common theme is the exploration of differences. Since the tigress and the viper are very different in nature, fanfictions often delve into how they overcome these differences. For example, the tigress is a large, powerful mammal, while the viper is a slithering reptile. Another theme is the idea of mutual benefit. They might help each other in the fictional stories, like the tigress providing protection and the viper providing something unique like venom for medicinal purposes in some stories.

Characterization is key. You need to understand the personalities of Master Viper and Tigress. Master Viper is sly and agile, while Tigress is strong and determined. You have to keep these traits in mind when writing their actions and dialogues.

Perhaps an ancient evil spirit that was sealed away long ago in Naruto's world but gets awakened by Ruby Lemon's presence. This spirit has the ability to possess people and use their skills for its own ends. It starts to cause chaos in the ninja villages and targets Ruby Lemon and Naruto specifically, seeing them as the key to either its complete destruction or its total domination.

It could be someone who also wants the power of the mask. Maybe a rogue ninja who has been researching the mask for a long time and sees Naruto as an obstacle to obtaining it.

One possible plot could be that the tigress, a fierce and independent character, meets the viper in an unexpected encounter in a mysterious forest. The viper, initially seen as a threat, turns out to have a kind heart. They start to bond over their shared love for the taste of lemons which are rare in their part of the forest. As they search for more lemons, they face various challenges together and their relationship deepens.

The storyline of the Tigress x Viper comic involves an intense and dynamic adventure where the two characters face various challenges and conflicts together.

It could still be Voldemort. Since he is the main villain in the original Harry Potter series, in this fanfiction he would see the Goddess Lemon as a threat to his plans of taking over the wizarding world. He might try to eliminate her before she can fully use her powers to help Harry and the Order of the Phoenix.

It could be an old enemy of Percy's who sees his relationship with Goddess Lemon as a threat. Maybe a Titan or a powerful monster that wants to use their relationship to its advantage, like using it to create a rift among the gods and demigods.