Shadow attack is just flavor text, it does nothing as far as I know (dark element base attacks do exist but I have not encounter any monster that is resistant or immune to only dark element).
The blind effect from potential replaces only the acc drop effect from panic, which causes two icon to appear, one to symbolize the damage reduction from panic, the other to symbolize the acc drop from the blind potential. If you were to use panic again on a monster with both icon, it will have only one icon again because panic acc drop effect replace the blind potential acc drop effect.
This bug is caused by being in any dialogue with any NPC when the timer run out.
To avoid this bug, do not talk with any npc when you are about to be kicked out for having no time remaining.
