歴戦余韻（二）

You're actually allowed unlimited Echo of War attempts per day. After completing your weekly 3, you can rerun Echo of War for free, but won't receive any rewards.

This is most likely a reference to the game ECHOES OF WAR: The Last Heartbeat. The game's premise basically has humans believing that their war against sentient machines is over, quite literally just leaving behind memories and echoes of what happened. But the main character of the game crash landed into a planet habited by a race of artificial intelligence thought to be extinct. So, they relive the fight, much like Trailblazers relive the boss fight in Honkai: Star Rail. - Credit: spAceLynn