Maybe some rogue Jedi who have turned to the dark side. They would know the temple's layout and weaknesses, making them tough opponents for Anakin.
He could face Sith Lords. They are always a big threat to the Jedi Temple.
In this fanfiction, perhaps Anakin defends the Jedi Temple from a sudden Sith attack. He might use his lightsaber skills and his connection to the Force to fend off the invaders.
The main storylines in the Anakin Jedi Temple comics include Anakin's growing doubts about the Jedi Order and his forbidden romance. Also, there are mysterious events and powerful enemies that test his skills and beliefs.
In this fanfiction, Anakin could interact with the spirit of Yoda. Yoda has a connection to both Anakin and the events in 'The Last Jedi'. Their exchange could be really interesting as Yoda has his own wisdom to impart and Anakin has his own experiences. Also, Anakin might interact with Leia. He knew her well in his own time, and in 'The Last Jedi' she is still an important figure. He could be proud of her leadership in the Resistance or have some concerns about the path she's leading her people on.
In many fanfictions, Anakin's betrayal by the Jedi Council is often depicted as a complex web of misunderstandings and power plays. One common take is that the Council's secrecy and lack of trust in Anakin, especially regarding his relationship with Padmé, pushed him towards the dark side. They constantly held him at arm's length, not fully accepting him despite his great power.
One possible different master for Anakin in fanfic could be Qui - Gon Jinn. Qui - Gon was always one to follow his instincts and was more in tune with the Living Force. He might have been able to handle Anakin's powerful emotions better than Obi - Wan. He was also more willing to question the Jedi Council, which could have influenced Anakin in a positive way, making him less likely to feel oppressed by the Council's rules.
Anakin could encounter future versions of his friends or enemies from the past. For instance, he could run into a future version of Obi - Wan Kenobi who has also somehow traveled to that future time. Or perhaps he meets a new generation of Sith who have different motives and methods compared to the Sith he knew in his own time. They could challenge his understanding of the dark side and the Force in general.
He could interact with Luke Skywalker. Imagine Anakin finally getting to meet his son as an ally in the Rebellion. They could train together and share their knowledge of the Force.
If that were the case, the galaxy's fate would likely have been very different. Maybe they could have avoided the conflicts and tragedies that came with Anakin's Jedi path. But who knows how other forces would have shaped events without the Jedi's influence.
Anakin as a Jedi Master in fanfiction could also be involved in diplomatic missions. Since he has seen the horrors of war and the corruption of the Sith, he would use his influence to promote peace among different planets. He might work with the Senate in a different way, trying to bridge the gap between the political world and the Jedi Order, all while maintaining his Jedi values and teachings.
There are indeed. Fanfiction is a vast genre, and many authors respect the original essence of the Star Wars story. They might write about a female Jedi training with Anakin, or them fighting side by side against the Sith. These stories are more about their heroism and growth rather than sexual relationships.