Warning: GOT spoilers ahead! Proceed with caution.
The war between the two queens continues to heat up (literally) on Game of Thrones, even as a frozen, undead army descends from beyond the Wall.
Think back to the Loot Train Battle in the season seven episode "The Spoils of War" — Cersei deals with her first major defeat, but it might not have been a total failure for the Mad Queen in training. In that episode, Randyll Tarly notes that the gold the Lannister army takes from Highgarden is already safely within the walls of King's Landing. Cersei then uses that influx of gold to pay her debts and borrow enough money from the Iron Bank to hire the Golden Company. "OK but what even is the Golden Company," you might ask? They are a sellsword company said to be 20,000 strong. Based in Essos, this band of exiles has a stellar reputation since they're known for never breaking a contract.
As we see in the riveting season seven finale, Cersei wants to use the money borrowed from the Iron Bank to hire out these men and have Euron bring them to Westeros on his ships in order to replenish her dwindling army. Just in time to defend them from the Night King's undead army, right?
In the season eight premiere, which aired on April 14, Euron makes good on his promise and arrives in King's Landing with the Golden Company and Captain Harry Strickland — an exiled knight of House Strickland and known in the books as "as Homeless Harry Strickland" — in tow.
Now that the Lannisters have lost even more soldiers, the Golden Company could be the key to keeping the devious queen in the game. In the books, the group of sellswords is made up of highly trained men willing to fight for anyone with enough money to pay them, and they take their jobs seriously. While sellswords in general are thought to be oathbreakers by nature (that's why Stannis declines to hire the company when Ser Davos suggests it in season four), the Golden Company takes great pride in their reputation. As a result, they keep their word once money exchanges hands. But just because they've never broken a contract before doesn't mean they never will, especially when it comes time to fight for Cersei and Euron.
The Lannister queen is making a smart move by bringing the Golden Company to King's Landing, there's no doubt about that. They are a ready-made army of trained men with battle experience. And since they are based in the Free Cities, they may have experience fighting against Dothraki Screamers, something the young soldiers of Westeros are clearly not prepared to do.
One potential downside is that she could be seen as bringing a foreign threat into the land, just like she accuses Daenerys of doing. But after the Loot Train Battle and the big wight reveal, her remaining allies will surely prefer the Golden Company's services over losing more of their own men to dragon fire or an army of frozen zombies. As a group, these sellswords could give Cersei major leverage, but there's one thing the queen isn't taking into consideration: the Golden Company could be swayed to Daenerys's side.
Targaryen bastard Aegor Rivers is the founder of the Golden Company. Many years before the events of Game of Thrones, he leaves Westeros and gathers the exiled knights and lords seeking sanctuary in the Free Cities to form a company of sellswords who stay true to their word. Even though this current iteration of the group never met Aegor, their company would not exist if not for a Targaryen. This could work in Daenerys's favor, especially when Jorah is factored in.
The newly cured Jorah is back by Dany's side, and his timing couldn't be better. Way back in season four, the Dragon Queen chastises Jorah for being suspicious of Daario's sellsword past because Jorah himself once worked for the Golden Company. That's right; before he is enlisted to spy on Daenerys and later switches to her side, Jorah worked for the most famous group of sellswords in the known world. Whether or not the knight left on good terms remains to be seen, but his passion for his queen could compel him to intercede on her behalf with his old band of brothers.
A dragon is responsible for founding the Golden Company, and even gold may not be enough to make them fight against the last Targaryen in the world (at least, the last one anyone knows about). Granted, their entire reputation is built on not breaking their contracts, but in the books, they compromise their motto to fight alongside a Targaryen who hasn't been a part of the show until recently — Rhaegar's supposed son, Aegon. Now that we know Jon Snow's real name is Aegon and he's the legitimate son of Rhaegar and Lyanna (and also the heir to the Iron Throne, NBD), there's an even stronger chance that the mercenaries could flip sides.
Whether the Golden Company follows through in their contract to fight for Cersei (or flips to Team Daenerys), look for this crew of sellswords to turn the tide of the war for whichever woman is lucky enough to contract them. A ready-made army with 20,000 fighters is bound to be formidable, whether they're fighting alongside dragons or against them.