Fool Me Once

[Tiger]

Jester must be incredibly easy, if you goggle him nothing is found. So how do you kill a boss that just keeps replacing every copy you kill with a new one?

[Nevvy]

You just have to find the real one in the bunch. It confused me at first too, but one of them is real and it doesn't change. So when he first splits try each of the ones that appears then until one takes a hit without vanishing, then kill him. He'll make more copies, but check only the new ones that appear. So on and so forth, I think he does it like three times total. Ya just gotta keep track of the ones you've shot before and narrow down the real Jester.

[Tiger]

Thanks, I just kept hitting the wrong doubles first!

[FMB]

If anyone else is stuck on this encounter, I figured out a way to cheese it:
Put Sally in your roster and equip her with a piercing weapon. Personally, I like the "Vicious Princess" because it is so her.

When you reach the final room, there will only be the one (real) Jester. Kill him, and three will spawn.
Use your other two characters that aren't Sally to try and figure out which of the three current Jesters is the real one and also, if possible, to clear out any barrels that might be in Sally's line of fire later.
Once you know where the real Jester is, move Sally to a spot where she can cover as much of the spawn locations as possible. Personally, I used the top left spot near an upright barrel so that I could cover the top and right spawns completely, the left spot about half due to barrels in the way. The bottom spot I could only reach via ricochet on a steep downward angle, but that was good enough.
Now activate Sally's "War Cry" for more damage and "Mad Dog" for unlimited Kill Shots.

If the real Jester is currently on his own, do not shoot him just yet. Instead, shoot one of the ones you know is fake, killing them instantly, and making a new one spawn at one of the spawn points. Keep killing fake Jesters until one of them spawns next to the real one. Then, shoot both of them (thanks to your piercing weapon). This will kill the fake one and damage but probably not kill the real one. Repeat until Jester is dead, ez pz.

[Soli]

Funny, on my last run, I just kept hitting the right one every time he split, and ended the fight in a few turns.
It was baffling. I never have that kind of luck.