This is slightly off topic while being on topic
SRD:
NEGATIVE ENERGY PLANE
To an observer, there’s little to see on the Negative Energy Plane. It is a dark, empty place, an eternal pit where a traveler can fall until the plane itself steals away all light and life. The Negative Energy Plane is the most hostile of the Inner Planes, and the most uncaring and intolerant of life. Only creatures immune to its life-draining energies can survive there.
The Negative Energy Plane has the following traits.
• Subjective directional gravity.
• Major negative-dominant. Some areas within the plane have only the minor negative-dominant trait, and these islands tend to be inhabited.
• Enhanced magic. Spells and spell-like abilities that use negative energy are maximized (as if the Maximize Spell metamagic feat had been used on them, but the spells don’t require higher-level slots). Spells and spell-like abilities that are already maximized are unaffected by this benefit. Class abilities that use negative energy, such as rebuking and controlling undead, gain a +10 bonus on the roll to determine Hit Dice affected.
• Impeded magic. Spells and spell-like abilities that use positive energy, including cure spells, are impeded. Characters on this plane take a –10 penalty on Fortitude saving throws made to remove negative levels bestowed by an energy drain attack.
Random Encounters: Because the Negative Energy Plane is virtually devoid of creatures, random encounters on the plane are exceedingly rare.
POSITIVE ENERGY PLANE
The Positive Energy Plane has no surface and is akin to the Elemental Plane of Air with its wide-open nature. However, every bit of this plane glows brightly with innate power. This power is dangerous to mortal forms, which are not made to handle it. Despite the beneficial effects of the plane, it is one of the most hostile of the Inner Planes. An unprotected character on this plane swells with power as positive energy is force-fed into her. Then, her mortal frame unable to contain that power, she immolates as if she were a small planet caught at the edge of a supernova. Visits to the Positive Energy Plane are brief, and even then travelers must be heavily protected.
The Positive Energy Plane has the following traits.
• Subjective directional gravity.
• Major positive-dominant. Some regions of the plane have the minor positive-dominant trait instead, and those islands tend to be inhabited.
• Enhanced magic. Spells and spell-like abilities that use positive energy, including cure spells, are maximized (as if the Maximize Spell metamagic feat had been used on them, but the spells don’t require higher-level slots). Spells and spell-like abilities that are already maximized are unaffected by this benefit. Class abilities that use positive energy, such as turning and destroying undead, gain a +10 bonus on the roll to determine Hit Dice affected. (Undead are almost impossible to find on this plane, however.)
• Impeded magic. Spells and spell-like abilities that use negative energy (including inflict spells) are impeded.
Random Encounters: Because the Positive Energy Plane is virtually devoid of creatures, random encounters on the plane are exceedingly rare.
neither positive nor negative energy are aligned. They are not good or evil.
Cure and inflict spells use positive and negative energy, but they are also not aligned.
Hence, having the evil overlord heal his troops is not a good act
