As an example, assume Glacors have 30,000 life points. If you were using magic and had a Magic level of 95, your dark magic damage would be the minimum of (95 + 1) * 15 (e.g. 1440 damage) or 30,000 * 0.05 (e.g. 1500 damage), or 1440 damage. So your first hit would be 1440, then 1152, then 921, then 737. Using dark magic can increase damage output by about 5-15% in the long term, although this is highly dependent on the monster's life points. This would also mean a significant boost in damage if one was using a wand+shield combo, more noticeable than dual wielding or using a staff.