Hello,
I casted an Ectopsychic Echo on Eder with my Cipher Watcher and it was still visible after the fight. Our group changed zone, nothing happens. Echo visual was still there. I quicksaved and loaded the save again, Echo was still there. I restarted the game, Echo visual was still there. I restarted Steam and loaded the game, visual has gone.
During that time, Echo did no damage to the others. Just visual.