oh, i didn't plan on dropping anyone or anything of the like, i was just curious about the process.
a player has a cloak of charisma +4, but basically wears it 24/7, so i figured it would just be considered normal. however, if she lost it or stopped wearing it, i'd probably re-adjust the followers over a week or so, maybe one week per dropped charisma bonus or something - certainly not immediate or anything.
during the attraction of the cohort, i know that a magic item's bonus would apply, but would it if the character merely cast eagle's splendor daily, or does it need to be a continuous bonus, such as the case of the cloak of charisma +4?