What Empathy can't do;
- Be used for healing. (If you want a squad healer, you need a Blood sorcerer.)
- Be used over a long distance during battle. Immediate surrounding are most likely to be affected first.
- Be used while actively fighting. It requires focus to use empathy.
- Be used on demons.
- Be used while casually riding/running around. Again, it requires concentration and focus.
What Empathy can do;
- It is the equivalent of a strong pain killer and can help make an injured squad member comfortable.
- During close combat, an Empath may use it to disrupt an opponent, but must be protected while doing so.
- Can sense nearby auras and possibly determine hostile intent.
- Can influence other beings to be more cooperative during interrogations or negotiations, or make hostile wildlife more friendly.
- If opponents are non-drow, empathy will have a more powerful effect on them, so long as the Empath is close to the group he wishes to affect.
These rules are a result of recent refinements to the setting, summed up here for your convenience.