A set of super powers that can be voluntarily transferred from person to person, but links each wielder's soul so they can never rest until the common archenemy is defeated. Ends up with a Hero Support Group composed of the souls of everyone who's had the powers for the last millennia. Also shenanigans involving transferring the powers to random bystanders to hide from detecting, roping an unwilling recipient into the network. Could be used for blackmail.