Owen K.C. Stephens
Adventurer
Off the top of my head, there are four things in offical WotC books that might help your party:
It’s expensive (+3 bonus), but the exalted special ability for armor gives you a permanent protection from evil. That would protect your fighter from any effort to possess him or exercise mental control over him (per the pro from evil spell description). (Book of Exalted Deeds).
Much cheaper is the Banner of Law, which puts protection from chaos on all allies in 1 30-ft. radius. (Again, no mental control on those protected). It’s noted that versions that cast pro from evil exist. However, it takes two hands to use, so you’d only want to whip it out after your fighter was charmed. (Heroes of Battle)
The very, very expensive cowl of warding provides a permanent mind blank (as well as freedom of movement and six levels of spell turning a day). (Magic of Faerun) It’s worth noting this item hasn’t been updated to 3.5 AFAICT.
And finally, the reasonably priced crystal mask of mindarmor grants the wearer a +4 insight bonus to all Will saves. (Expanded Psionics Handbook)
Owen K.C. Stephens
d20 Triggerman
It’s expensive (+3 bonus), but the exalted special ability for armor gives you a permanent protection from evil. That would protect your fighter from any effort to possess him or exercise mental control over him (per the pro from evil spell description). (Book of Exalted Deeds).
Much cheaper is the Banner of Law, which puts protection from chaos on all allies in 1 30-ft. radius. (Again, no mental control on those protected). It’s noted that versions that cast pro from evil exist. However, it takes two hands to use, so you’d only want to whip it out after your fighter was charmed. (Heroes of Battle)
The very, very expensive cowl of warding provides a permanent mind blank (as well as freedom of movement and six levels of spell turning a day). (Magic of Faerun) It’s worth noting this item hasn’t been updated to 3.5 AFAICT.
And finally, the reasonably priced crystal mask of mindarmor grants the wearer a +4 insight bonus to all Will saves. (Expanded Psionics Handbook)
Owen K.C. Stephens
d20 Triggerman