“Judge Magister of the Archadian Imperial Army, director of the 2nd Bureau. A warrior by training, he has a personal affinity for weapons and combat. His experience with warfare has positioned him as the Empire's preeminent Judge overseeing invasion and military envoys. A staunch supporter of Lord Vayne (also a believer in administration by force). he has dedicated his life to ensuring Vayne's aspirations come to fruition.”
The original Japanese version of this battle is different.
At the start of the battle, Judge Bergan is flanked with Imperial Judges. The Imperial Judges serve mostly as a shield and distraction for Judge Bergan. When the majority of Bergan's HP is drained, he will use Battle Cry, which increases his Defense and raises his Attack power. Judge Bergan is vulnerable to Sleep.
It is best to lure the Imperial Judges away from Bergan to the other side, and hopefully kill at least one Judge before Bergan pursues. It's best to defeat the Imperial Judges first and minimize the damage taken before focusing on defeating Bergan.
If the party is getting overwhelmed, one can summonMateus and let him shield the party while recovering. Another strategy is to immediately use a Quickening chain on Bergan. As he has low HP for a boss at this point in the game, a Quickening chain along with a Concurrence can overwhelm the Judge, and two Quickening chains, if the party has at least one for every character and two for each in the main party, will be enough to defeat Bergan if chained correctly.
Bergan is fought in Stage 100 of the Trial Mode alongside the other Judge Magisters. Bergan is the main physical damage leader of the quintet and has the highest HP. He only attacks, but Zargabaath casts Bravery and Berserk on him, making Bergan a dangerous foe to deal with.
If all party characters are in Reverse, Bergan will do nothing until it runs out. However, if Bergan is Berserked he will not hold back and can thus become a good source of healing. One must be careful, however, to not let Reverse run out at a critical moment, or else Bergan can quickly KO the character.
Bergan is vulnerable to Disease, but if Ghis and Drace are already dealt with, this is irrelevant as neither Gabranth nor Zargabaath use Elixirs on Bergan. Bergan doesn't use any Elixirs himself.
Bergan should be dispelled as soon as he is buffed by Zargabaath. If the party casts Protect and wears good armor, even Bergan will not do a lot of damage. He walks slowly, so it's possible to run away from him with the character he targets. Bergan will catch up but this cuts down the amount of hits one has to endure.
It's also possible to repeatedly use the Wither technick on Bergan, massively reducing his Strength. After a few successful Withers, Bergan will be harmless. Since Bergan is incapable of harming a party member in Reverse, using it will make Bergan static. As long as the player has the means to deal with the Elixirs thrown by Ghis, and X-Potions thrown by Gabranth, this may be the safer option compared to taking Bergan's hits.