Synthesis

Synthesis basically means combining two items to get a single synthesized item with some of the properties of each of the input items. In all cases there is one base item and one other item. The second item will be destroyed as part of the synthesis process, but its mark(s) and/or enhancement levels will be transferred to the base item. There are several cases depending on what types of gear you're using.

## Swords and Shields

In the original game, Smith Oyakata will synthesize two swords together or two shields. In the sequel, Lina serves the same role. They both charge a modest fee for synthesis. They'll also allow you to see what the synthesized item will be before finalizing the operation, so you can cancel it if it wasn't what you wanted.

In both games, the new enhancement value of the synthesized item will be the sum of the enhancement values of the inputs, at least unless that exceeds the cap of the base item. For example, if you synthesize a +3 sword with a +2 sword, the result will have an enhancement level of +5. However, if you synthesize together two +25 swords and the base item has an enhancement cap of +30, the result will only have an enhancement level of +30, not +50.

Purple marks are ignored during synthesis. All marks of other colors will be transferred from the second item to the base item, so long as there are enough open mark slots. You can ask Oyakata or Lina to remove unwanted marks in order to make room for the ones that you want. A sword or shield can only have one red mark, however, so if both of the items to synthesize had a red mark, the one from the second item will not transfer to the first one. It will transfer blue marks, even though multiple copies of the same blue mark are redundant.

In the sequel, most swords and shields come with an intrinsic mark that cannot be removed. In the original game, it was just the first mark on the item and could be removed to free up the slot like any other mark.

After you beat the first six dungeons of the original game to open the Mysterious Adventure dungeon, Oyakata gets an improved version of synthesis. If you synthesize two items with the same name, the maximum enhancement level of the resulting item will increase by 10, up to a cap of 99. To determine whether two items are the "same", only the base item counts, not other stats or marks on it. For example, if you synthesize a Bronze Sword with a Steel Sword, the items are different, so it won't increase the maximum enhancement level. If you synthesize an Alone Steel Sword with a Brave Steel Sword, they are both a Steel Sword, so they count as the same sword and will increase the maximum enhancement level.

## Fruit

You can't synthesize together two pieces of fruit. You can, however, use a piece of fruit as the second item to synthesize it together with a sword or shield. This converts the fruit into a mark that is added to the sword or shield. It does not change the enhancement level. Once a mark is added by fruit synthesis, it can subsequently be transferred or removed like any other (non-purple) mark.

In the original game, synthesizing a piece of fruit is done by Compounder Barbara and is called special synthesis. As with Oyakata, she charges a modest fee and will let you preview the results before you finalize the operation.

The sequel doesn't yet have Barbara or any successor character. Rather, if you put the sword or shield into a Synthesis Pouch first, and then add a piece of fruit to the same pouch later, it will convert the fruit into a mark and add it to the base item. Unlike Barbara, this does not allow you to preview the item before the synthesis actually happens. Furthermore, some types of fruit do not generate marks in this manner. You can get the synthesized item out of the pouch by throwing the pouch at a wall, which will shatter it and spill its contents onto the ground.

## Bracelets

In the original game, bracelets have some intrinsic effect and do not use the mark system. You cannot synthesize bracelets together in the original game.

In the sequel, however, most (but not all) bracelets have an intrinsic mark, as well as an empty mark slot. If you synthesize two bracelets together using a synthesis pouch as explained in the fruit section, it will transfer the mark of the second item into the previously empty slot on the first. This effectively allows you to combine the effects of two bracelets.

## Staffs

In the original game, you cannot synthesize staffs together. In the sequel, you can synthesize two of the same staff together using a Synthesis Pouch. This will add the number of charges remaining together, effectively giving you the same number of staff uses as before, but while using only a single inventory slot. According to the JP wiki, the maximum number of charges a staff can have is 30. Incidentally, even though some books have charges, they cannot be synthesized in the same manner as staffs.

## Pot Fairy

The Pot Fairy, along with the Item Eater, Collecter Pot, and Inhaler are a family of monsters introduced in the sequel who are notable for having the ability to perform synthesis. With a friend, the player can throw the base item at the Pot Fairy, followed by the second item, and the fairy will synthesize them if possible and drop the result on the ground. She will not accept items if her like level is not at max, and performing synthesis will reduce her like level by two hearts. If a base item has been given to the fairy but the player changes their mind and doesn't want to synthesize it, they can send the fairy home and she will drop whatever she was carrying on the ground. Note that she can also grab items thrown or shot by enemy monsters, and will similarly attempt synthesis and lose like level if she ends up with two in her pot.

Enemy Pot Fairies can also be used to perform synthesis in a similar manner. The player can throw two items at an enemy fairy and they will perform synthesis, then defeat the fairy in order to retrieve the resulting item. In this case they do not require a high like level, but they cannot be asleep or paralyzed, and their attack power is increased with each item thrown to them.

Due to this ability, having one of these monsters as a friend can be very helpful to the player, though they cannot be recruited until the player unlocks crafting in order to create an Elixir.