The Staff of the Meek allows even the frailest fighter to strike with great might. In fact, it relies on weakness for its strength. While wielding this staff, you use the inverse of your Strength modifier (-2 becomes +2, +3 becomes -3) as your attack modifier and the inverse of your Constitution modifier as your damage modifier.
This is Jeff’s (JaH) starting magical item (sort of, 5e and Mind Weave are very different). It’s well suited for a scrawny mage who thinks he can be a hero in the traditional sense of standing against the enemy and filling the breach. It allows the GM to give a weak melee fighter a chance without being the kind of thing that gets too powerful in the barbarian’s hands.