[Mathias]

How does the rune function - do you want it to be applied to all longswords (if so, that's "all things"), or do you want it to select one of the two longswords your character owns (if so, that's "picks on hero").


Here's some things to copy from that are outside of a weapon, but are choosing a weapon and applying extra damage:

Class special: "Deed: Overload" (from people of the wastes)
Racial Custom Ability: "Bleed" (this is an eidolon thing from champions of corruption)
Racial Custom Ability: "Grab" (also an eidolon thing, this one from the APG)
Class Special: "Cut the Corruption" (order of the green archetype, from heroes of the wild/ultimate wilderness)


They'll give you better examples of how to apply this sort of thing in the specific context you want to apply it within.