Amazon's Lord of the Rings TV Series, The Rings of Power, is due to be released later this year and it is likely that the Balrog will make its terrifying return and give audiences a glimpse of its backstory. With a look similar to Peter Jackson's movies, The Rings of Power will follow a variety of heroes throughout the Second Age of Middle Earth, years before the events of The Lord of the Rings and The Hobbit. Many of these heroes will be unrecognizable and new to viewers; however, the elves Galadriel and Elrond are due to be prominent characters. Sauron is also confirmed as a major villain, and it is with him that the Balrog is likely to make a reappearance.
When the monster was last seen, it was dragging Gandalf down from the bridge of Khazad-dum in Moria. This was followed by an epically long battle throughout the Misty Mountains between the two Maiar, demi-gods of Middle Earth, and the Balrog's eventual demise at the hands of his foe. It was after this battle that Gandalf was reborn as the more powerful Gandalf the White. As Maiar, these characters are deemed extraordinarily powerful, having left Valinor and the safety of the gods for Middle Earth. But each serves a very different purpose and it is in their final moments that the strength of each is tested.
While the Balrog's demise was highlighted in The Lord of the Rings, it is likely its history will be thoroughly explored in The Rings of Power due to its connection to Sauron. Before Sauron, Morgoth was the major antagonist of Middle Earth and Sauron learned from this leader to crave power. In Morgoth's, and later Sauron's, armies, there were many Balrog among the trolls, orcs, and goblins that followed them. These Balrog were also Maiar and extremely powerful, many rising to the ranks of generals within both respective armies. With Sauron shaping up to be The Rings of Power's main antagonist again, his armies will play a large part in his progressive invasion of Middle Earth and so, therefore, the Balrog will likely return to screens.
In the prologue to The Fellowship of the Ring, audiences were introduced to the final battle between man, elves, and orcs, against Sauron's forces - a final push from the free folk of Middle Earth. With Isildur removing the ring from Sauron, and the villain's loss, the evil creatures of Middle Earth scattered and hid. However, it appears that the Balrog was in hiding before this moment, not featuring in this final battle. The Balrog appears in Moria in The Lord of the Rings, the dwarven halls underneath the Misty Mountains. King Thror, the builder of these halls, is also confirmed to appear in The Rings of Power, alongside his controversially beardless dwarven wife, Disa. It's entirely possible viewers will see him discover the Balrog in the mountain's depths or that the Balrog will be tasked with destroying the dwarves by Sauron.
These questions will, unfortunately, remain unanswered until later this year and the release of the first season of The Rings of Power. However, due to the setting's era and the nature of Sauron being a focal villain within the series, as confirmed with the many teaser posters for the series, the Balrog will surely return. From there, its origins in the realm of Moria will hopefully be explored and longstanding questions will be given answers.