There should be a way to "back out" of a relic opening, if you haven't actually opened one yet. There has been several times when I have accidentally clicked on a relic, and been taken to the relic open screen, to realize that I mistakenly clicked the wrong relic. (For example - I would like to save the relic shards for an exchange). There currently is no way to cancel. And if you close the game, those relics either disappear, or are automatically opened (I haven't been able to determine what happens) they are gone when restarting the game, and characters do not appear in the "new" tab.