How often does the characters change around in the exchange?

thomascj300

I can see that every few hours the exhange resets so you can buy more of the same character tokens, but how long will those characters stay in the exhcnage? I want to start buying tokens for the exclusive characters like Hades, but worried that they'll disappear from the exchange and leave me with not enough tokens!

PapaBearded

General thought is that the exclusives will stay in those locations, and that toons would be added, not removed.