No, the Jougan is not considered a filler in the Naruto series. It is a unique dojutsu possessed by Boruto Uzumaki, the main character of the sequel series "Boruto: Naruto Next Generations." The Jougan has been shown to have special abilities and significance in the story, making it an important aspect of Boruto's character development and the overall plot of the series. **

Boruto inherited the Jougan from his father, Naruto, who possesses the ability to sense negative emotions and see the chakra pathway system. The Jougan is a unique dojutsu that is said to be a combination of the Byakugan and the Tenseigan. It is believed that Boruto's exposure to the Otsutsuki clan during his battles and encounters may have triggered the awakening of his Jougan. **

The Jougan, also known as the Pure Eye, is a special dojutsu possessed by Boruto Uzumaki in the Naruto series. It is said to have the ability to see and sense chakra, as well as perceive interdimensional and spiritual energies. With the Jougan, one can potentially see through illusions, detect hidden enemies, and even perceive the flow of time and space. Its full capabilities are not yet fully explored in the series, but it is a powerful tool that can provide a significant advantage in battle and in understanding the world around the user. **

Boruto inherited the Kekkei Genkai Jougan from his mother, Hinata Hyuga. Hinata possesses the Byakugan, a powerful dojutsu that allows her to see chakra points and have a 360-degree field of vision. It is believed that Boruto's Jougan is a combination of the Byakugan and the Otsutsuki clan's mysterious powers, making it a unique and powerful dojutsu. **

The Jougan first appears in episode 15 of Boruto: Naruto Next Generations. In this episode, Boruto activates the mysterious eye during a battle with Nue, a creature from another dimension. The Jougan's appearance marks the beginning of Boruto's journey to understand and master this unique eye power. **

It is difficult to definitively say whether the combination of Jougan and Karma is stronger than Nine Tails and Sage Mode, as the power levels of these abilities are not clearly defined and can vary depending on the situation. However, both combinations are incredibly powerful in their own right, with Nine Tails and Sage Mode being iconic abilities of Naruto, and Jougan and Karma being unique to Boruto. Ultimately, the outcome of a battle between these combinations would depend on various factors such as the skill and strategy of the users, the specific circumstances of the fight, and the narrative direction of the story. **

The Sharingan is the strongest, followed by the Byakugan, and then the Jougan. The Sharingan is known for its ability to see chakra, predict movements, and cast powerful genjutsu. The Byakugan is also powerful, with its ability to see through objects and perceive chakra points. The Jougan, while still mysterious and not fully explored in the Naruto series, has shown some unique abilities but has not yet demonstrated the same level of power as the Sharingan and Byakugan. **

So far in the anime, the Jougan has demonstrated the ability to perceive and interact with chakra, allowing Boruto to see the flow of chakra and its disruptions. It has also shown the power to see through dimensions and perceive invisible barriers. In the future, it is speculated that the Jougan will gain the ability to see the chakra pathway system and potentially even manipulate space-time, allowing Boruto to travel between dimensions and possibly even see into the future. **