CoF resonance

My brother and I were looking into this game and we are curious if it had been stated whether they are used to trade with someone’s account or their character. I ask because we normally play games together but his free time is significantly less than mine. I normally play a character solo and the a different character with him until we reach “endgame” and then I switch back to my main character. Will the resonance we earn be able to be used to trade with each on my main character or will we need to earn resonances over again? Thanks for any info.