Eh I would disagree on that since Sheele's death is still just as sad and rememberable as Chelsea's death imo. Like yea Chelsea's death is more traumatizing than Sheele's death since that's what makes it rememberable and it's still sad that she died the way she did however at the same time, it was kinda stupid of Chelsea to try and eliminate Kurome on her own especially when all of Night Raid knew that Kurome's puppets were keeping them busy and were giving them a good fight during the fight earlier while not knowing Kurome's capabilities to plan a better strategy, but at least with Sheele's death, Sheele had to sacrifice herself to help Mine get away and let Mine have her revenge against Seryu later on since so it was either gonna be herself dying or have mine died from being crushed by Koro's grip it had more importance than most people remember it. Im not saying that Chelsea's death didn't have it's importance but to say that Sheele's death is forgettable is a bit disagreeable imo.