Greetings once more, SevenFold!
Thank you for your patience with the wait for a response to your report. Unfortunately, it seems that the development team requires more specific information about your experiences. It would be a great help if you provided information about whether the icon that you refer to is on the monster itself, or is this an icon that you received on your character after a monster casted magic on you. In addition, it would also be very helpful if you could clarify whether you refer to the mob casting a spell on itself or you casting a spell on yourself when you mentioned the self-casting ability in reference to seeing the Monsters HP bar disappearing. Any other specific details that you can provide (e.g. the names of the mobs that you have experienced these problems with, the names of the self-casting abilities used, etc.) would be a great help to clarify what conditions are needed to try to recreate what you have experienced. Thanks again for your patience!