there is a bug where when you apply modifiers to weapons, they default to the worst ones. Example: Mythical tunrs into Lazy or Ignorant. (This is probably not a bug, but something that ReLogic did to combat the use of this)
If you apply an incompatible modifier, the game changes it to whatever it feels like when you load the character.
I’m yet to figure out a reliable way to tell which modifiers an item is compatible with to indicate this in Terrasavr.