S Rank Elite Marks should outright have a ridiculous amount of HP and a set timer upon first engagement for it to be downed. Something like Odin, but way more HP. Maybe 100 million HP and to be killed within 10mins if engagement? Then people won't be able to zerg it down easily and have to call for as many people as they can to defeat it, instead of some being assholes who killed them at first sight before any other could even have a shot at it.