The Necroflux is an electric ghost, probably something to do with weird Frankenstien experiments, storms during powerful planetary alignments, or an execution. This creature always inhabits a piece of metal. When it jumps from metal to metal it trails lightning between. Creatures killed by it are re-animated as electro-zombies.
A Necroflux notices when living creatures come near and waits for a good opportunity to attack. It will try to arc to someone in metal armor, since it’s difficult to take the armor off. Anyone between the start and end of the arc gets hit by a 3d6 Lightning Bolt (including anyone wearing or holding either piece). The arc can be up to 40′, or 80′ if both pieces of metal are connected by water. A given Necroflux can’t arc to the same piece of metal ever again. Consider a suit of armor as one piece of metal (chainmail for example) but if your rules count a helmet as a separate piece then it’s fair game. Shields are typically wood and leather unless your game specifies.
A Necroflux can shock the wearer / bearer of the metal it inhabits instead of arcing, for just 1d6 damage (no save).
Very small metal pieces can’t hold it. Ignore things like coins, belt buckles, sewing needles, and arrowheads. Include things like daggers, metal flutes, and grappling hooks. If it’s 1 pound or over in one piece, it’s possible.
The metal is unharmed by the arc.
Anyone slain by the electric attack will rise in 1 turn as an electro-zombie under the general command of the Necroflux. It shambles with a jolting gait, is immune to electricity, but if immersed in water it shorts out and dies. Can be turned. Stats are otherwise as “Zombie”. Electro-zombies tend to gather up metal objects and carry them around, providing the Necroflux some mobility, though it’s not intentional and won’t happen in combat.
If a Necroflux jumps into an intelligent sword (or similar) there is a lightning-fast battle of wills. Roll 3d6, and if the result is under the sword’s Ego the Necroflux is ejected automatically and hangs in the air as a man-shaped electric cloud for 1d6 rounds. This is the same thing that happens when you turn it (although a “destroy” result still means it’s destroyed). An ejected Necroflux can’t move or act, and in this state it’s most vulnerable (HD 3, AC 6).
If you hit an ejected Necroflux with a metal item, it arcs into the item without harm, although it remains stunned for the rest of its ejected duration. If you destroy a metal item holding a Necroflux using a metal tool the Necroflux arcs into the tool without harm. If you destroy the metal item using a non-metal tool the Necroflux has nowhere to go and it’s ejected as above.
If an ejected Necroflux ends its stun duration and there’s no metal within range it can arc to, it dissipates (dies).
Necrofluxes are found in a place with plenty of metal to arc to, such as an old battlefield or dungeon, or else in the bottom of a deep hole trapped in a hand axe or something.