Barbed devils have a passive physical attack that involves you getting pierced by their barbs. Possibly if you are wearing body armor and/or gloves, or wielding a two-handed weapon with longer reach, the passive attack may not always hit you. (Polearms should never incur this attack, but the way passive attacks work by default should already ensure this.)

Cursed two-handed weapons only weld to one hand at a time, allowing you to do things with the other hand. The only way to have no free hands at all is to wear a cursed shield and wield a cursed weapon.