With Fate/Grand Order's Sixth Lostbelt on the horizon, it's the perfect time to reflect on when the Mage King Solomon destroyed the future by tampering with the past, creating Singularities. By making these specific points in time when events have disrupted the timeline beyond repair, Solomon seeks to end humanity and the cycle of mistakes and damage that will follow.
With every prospecting Master who could thwart his plans put out of commission, it's up to Ritsuka Fujimaru and their Servant, Mash Kyrielight, to warp back in time and fix the anomalies. As the pair goes further back in time, the trials only get longer and harsher, but a Heroic Servant's job is never done.
9 Flame Contaminated City: Fuyuki
The very first Singularity, which technically isn't one of the main ones, is the easiest. As Fuyuki was essentially the game's tutorial, most fights comprise pathetically weak skeletons and Shadow Servants to get players acclimated to the class system and the battle mechanics.
The biggest challenge of this area is the final battle against Saber Alter, who makes a point of how strong bosses will become further into the game. Ironically, when FGO releases their yearly Memorial Quests, the Fuyuki quest is among the most difficult. In the quest, Saber Alter has a buff that fills her Noble Phantasm gauge every turn, allowing her to nuke the player's team repeatedly.
8 Eternal Madness Empire: Septem
The second Singularity, set in Ancient Rome around the time of Nero Claudius, landed Fujimaru and Mash into a civil war between previous Roman emperors such as Julius Caesar and Caligula. The battles in this Singularity aren't too challenging, as they're composed mostly of common foot soldiers, which are among the weakest kind of enemy in Fate/Grand Order.
Most of the area's challenges come from the boss fights, a few of which are Berserkers which deal extra damage to all other classes except Shielder. Unprepared Masters may have had a tough time against Caligula and Darius in particular. Otherwise, progress is a smooth process in Septem.
7 Hundred Years' War Of The Evil Dragons: Orleans
The first official Singularity, Orleans, is set in France soon after the Hundred Years' War and following Jeanne d'Arc's execution. When a Rogue Servant uses the Holy Grail to create an Alter of Jeanne, one that despises humanity, the original Jeanne teams up with Fujimaru and several more Servants to stop her dark counterpart from razing the world with dragon fire.
Orleans's normal fights are somewhat easy, mostly made up of foot soldiers and wyverns which quickly go down to Assassins. The Singularity's real difficulty comes from the bosses, especially Jeanne Alter. Her Ruler class is brutal to early players due to its near immunity to all other classes besides Berserker.
6 Sealed Ends Of The Four Seas: Okeanos
The third Singularity, Okeanos, is set in the Atlantic Ocean amidst a chain of islands. It's a journey for gold and glory on the high seas with Francis Drake and a ragtag crew of misfit Servants against Blackbeard and his gang.
Okeanos is a moderately difficult Singularity, to the point where even the final boss against Medea and the Demon God Pillar is laughably average. The challenge comes solely from the Heracles boss fights, who has the power to revive almost indefinitely and whose Berserker gives grants him additional damage to all Servants that aren't Shielders or Foreigners.
5 The Mist City: London
The fourth Singularity, London, is set in the titular capital of late 19th-century England. The city is shrouded in a deadly fog and the streets are stalked by an even deadlier serial killer: the infamous Jack the Ripper. London is largely a mystery story that also serves as the first step towards advancing the plot with Solomon and his plan to eradicate human history.
Enemies in London, while they aren't much stronger, come with more useful skills that force players to approach battles more carefully. The bosses aren't anything to write home about aside from Nikola Tesla and his ability to charge his gauge, as well as Solomon himself, who's practically invincible, even when holding back.
4 North American Myth War: E Pluribus Unum
The fifth Singularity, E Pluribus Unum, is set in an alternate version of the 18th-century United States where American troops are deeply embroiled in a civil war against the Celts. On one end of the conflict is the American army, led by Helena Blavatsky, Nikola Tesla, and a transformed Thomas Edison.
On the other side are Queen Medb and her host of Celtic warriors, including Fionn mac Cumhaill and an Alter version of Cu Chulainn. Cu Alter alone is enough to give some players a run for their money. With multiple defensive skills, an explosive Noble Phantasm, and absurdly high health, he's likely the first big hurdle for new players.
3 The Grand Temple Of Time: Solomon
Solomon, the final frontier where every player's skill and experience up until that point is tested, proves challenging, but not the nightmare that last levels are in other games. Most of the Singularity's fights comprise Demon God Pillar bosses that can be put down quickly with a decent team.
As the original fights are presented in Fate/Grand Order's raid format, the final battle is a victory lap. The true horror comes in the form of Goetia, one of the Demon Gods contracted to Solomon and the true villain behind the scorched Earth plot. By contrast, his fight is truly a nightmare, especially when he's exploiting his Noble Phantasm and vast array of skills.
2 Divine Realm Of The Round Table: Camelot
The first big hurdle for new players came in the form of Camelot, set in Jerusalem during the late 1200s where the Knights of the Round Table are locked in a deadly feud with the Order of Assassins and the forces of Ancient Egypt. Led by an aged-up goddess form of Saber dubbed The Lion King, the Round Table seeks to safeguard humanity against Solomon's calamity by sequestering them in her ideal holy city.
Each of the Round Table knights is given a boost thanks to the Lion King's Holy Grail, which turns already challenging fights into absurdly hard slugfests. Gawain, in particular, is infamous for his fight that teams were specially built to deal with him.
1 Absolute Demonic Front: Babylonia
The final main Singularity, Babylonia, is a massive battleground where the last bastions of civilization in Mesopotamia weather the assault of a trio of goddesses. Babylonia is set during what the Fate franchise refers to as the Age of Gods, where magic was at its peak and humans were still associated with the divine.
As a result, opponents are much tougher compared to those of the modern era. In Babylonia, even the common mobs will give players a hard time if they aren't careful, especially near the end. The battles in Babylonia gradually ramp up until the climactic battle against Tiamat, who throws everything and the kitchen sink at the player; fitting for an entity worthy of the Beast class.