I just want to add, experienced Bards can do high damage but Bard isn't exactly a high damage DPS class. If your friend is having troubles it might be worth switching to maybe Ninja where you can still do decent damage if you mess up. The rotation is a little harder but it's a lot more forgiving compared to playing a low damage class, especially if it's not being played to its full potential (of course it's no fault of your friends). Also please report those people in the dungeons, that's horrible. Good luck to your friend!