Energy Charge, Revised (3.5e Creature Ability)

Energy Charge, Revised
This supernatural ability sends a burst of vital energy through a touch, which automatically happens when the specified attack hits. Each successful energy charge bestows one or more positive levels (the creature’s description lists how many) on creatures. Unless otherwise specified in the creature’s description, a draining creature loses 5 hit points for each positive level it bestows to a living creature. (It gains 5 Temporary HP when doing so to an undead, see below)

A creature with this ability can turn it on or off as a free action.

If a living creature has negative levels when they are hit with an energy charge, they lose a number of negative levels equal to the number of positive levels they would have received. Likewise, if a creature has positive levels when they are hit with an energy drain, they lose a number of positive levels equal to the number of negative levels they would have received. Any leftover positive or negative levels are applied normally.

An affected creature gains a +1 competence bonus on all skill checks and ability checks, attack rolls, and saving throws, and gains 5 hit points. A creature may not have more positive levels than its Constitution bonus (minimum 1). Positive levels remain for 24 hours or until removed with a spell, such as restoration. After 24 hours, the positive level automatically goes away.

An energy charge is not only useful to empower allies, it is also possible to harm undead with an energy charge.  The creature gains 5 temporary hit points for each positive level bestowed on an undead. These hit points only last for one hour.

Undead react to positive levels the way nonundead react to negative levels. An undead character with negative levels at least equal to its current level is instantly destroyed. After 24 hours, an undead must make a Will save (DC 10 + 1/2 attacker's HD + attacker's Cha modifier). (The DC is provided in the attacker's description.) If the saving throw succeeds, the positive level goes away with no harm to the creature. The afflicted creature makes a separate saving throw for each positive level it has gained. If the save fails, the positive level goes away, but the creature's level (or HD) is also reduced by one.

When determining if the creature meets prerequisites, the energy charge can be considered to be an energy drain attack, and feats or abilities that activate when the energy drain ability is used (Such as the Soul EaterBoVD prestige class or the Spell DrainLM feat) are activated when a positive level is given to an undead creature.