I keep referring to this game as simply Octopath but the real name of it is "Octopath Traveler" or in the case of the one I am playing now "Octopath Traveler 2." The reason for this is because there are 8 characters and their stories eventually intertwine into one central story that you are not meant to see coming. I am what I think is about 75% of the way through the 2nd installment of the franchise and I am only just starting to see how their stories coincide with one another.
The game isn't terribly difficult and could be considered casual by most people's standards but there is one thing that is quite difficult and gets even harder as the game goes on and that is the bosses. These fights can take quite a long time and in just a few rounds you can find yourself getting your entire party wiped in what is sometimes a rather cheesy manner.
Two of the main tactics that the enemy will use to totally wipe your part are two status effects that you rarely see in any other encounter and they are called "blind" and "terror."
These status effects seriously harm your ability to both defend and cause damage and need to be dealt with as quickly as possible in order to prevent your team getting wiped.
One thing I find a bit cheesy about the later boss fights is that they are specifically designed to have you get nearly to victory and then the boss whips out a series of attacks that they do not use up to that point and then totally cream your party and this can sometimes be after you have spent 20 minutes or so on the fight. In almost all of the instances of this happening to me, it has been specifically because of these two status afflictions.
Terror disables your ability to power up any attacks and blindness makes it likely that your attacks are going to miss. You need these aspects to not be on you in order to avoid getting wiped.
The "best" way of avoiding these status effects is to have an item equipped that makes your character immune to the status effect but by design, there are not enough of them available in the game for your characters to all have one of them. In the case of preventing terror, there are only 2 total available items and this means 2 of your characters will be affected. In the case of blind the total number is 2.
Therefore, the better method of dealing with this is to instead assign the job of apothecary to whoever you have with your party that is your primary healer and also equip both of the prevention items to that same character. Then, you can use their apothecary skills to remove the status effect from the rest of the group.
The first time I really saw this was vs the boss called "Mother. The fight appears to be going in your favor but then she whips out consecutive rounds where it is kind of full of shit as she inflicts terror on your entire group while also making her shield bigger than it normally would be. The same thing happens later with other bosses using the same method but with perhaps blindness instead of terror. Either of these afflictions seriously disable your ability to break their offense and if you don't do so they have a later attack that is basically a ticking time bomb that you are going to die from. There is a certain skill you can equip that will auto resurrect you if you are brought to zero HP but the game knows this and cheeses you by giving some of these bosses one addition attack that will kill you a second time.
I think it is full of shit but hell, these later boss fights are supposed to be tough, right?
I think they built this in because the apothecary character named Castti, is a character that I think most people find a bit useless and therefore don't put her in the party very often. Well, you are going to need her or at the minimum her job assigned to someone else in your party to quickly deal with this issue.
By using the appropriate apothecary skill by combining either the Herb of Light (cures blind) or Herb of Valor (cures terror) with whatever the other item is that applies this cure to all characters. The real advantage to having Castti in your party instead of assigning just the job to some other character is that there is an elite skill that she has that doesn't actually consume the herbs in your inventory to use the skill. Someone else that has the job assigned to them will consume these resources in your inventory, and whatever the one is called that applies the cure to all in the party is extremely rare.
I spent most of the game feeling as though Castti was rather useless only to realize later in the game that she and her job skills are some of the most important of any character in the entire game.
I don't think it is very likely that you are going to win some of these boss battles without using these cures unless you are seriously overpowered before entering the battle to begin with, and since grinding for XP is one of the only lame aspects of the entire game, you should go ahead and embrace that Castti needs to be a part of your party as often as possible.
These boss fights are very long and it can be a bit of a downer to spend 20 minutes dominating a fight only to face the "final stage" of the boss and get wiped in 2 rounds after basically dominating the rest of the fight. This is caused almost exclusively by status effects and well, this is how you get past them.
tl;dr - You need Castti's apothecary skills to clear status effects of blind and terror (as well as others) in order to defeat later game bosses.