Acquire Powerful Weapons Easier
There is an easier way in which to acquire more powerful weapons for your characters that you have unlocked. As you progress through a kingdom's Story Mode, you will eventually reach the end. What you need for this is a battle that has a camp beforehand, which will house a Blacksmith for weapon buying.
Go to that stage, preferably the last one (all Hypothetical routes' final stages have a camp before battle), choose Play All and then set the difficulty to Chaos. Now, you can go to the Blacksmith and almost all of the weapons for sale will be three or four-dot weapons with a lot of skills on them. Once you purchase what you want, save via the menu and then you can quit back to the main menu.