Encounter cards with charges? (rules question)

By rholdenl, in Relic

So, we're playing with Librarium and training grounds. Both state gain 1 willpower and 1 power for spending one charge respectively. Is this gain permanent or until end of turn?

It's permanent. They're basically stat pools that help you improve your attributes faster, each turn you encounter one. Once a player discards the last charge token on the card, it is discarded from play.