For technical users, editing the Fontfly LNS save data using an ANSI editor and changing specific background data values (typically to "10" or "11") has been reported to bypass character locks.
Boss Rush mode is the quickest way to unlock the entire roster if you can master the difficulty, as it bypasses standard levels. 2. The Save File Edit (Working for v4.3) final fight lns ultimate unlock all characters work
I can provide tailored system instructions based on your setup. Share public link For technical users, editing the Fontfly LNS save