“The crate push”, every week we get a dungeon from a rotation of all dungeons that have ever been in M+, 1 dungeon that entire week. No affixes, infinite scaling, separate key. The goal is to push that one key as high as you can, it doesn’t downgrade, it doesn’t give gear, etc.
You get a bar like with the trading post, and there’s a crate on the marker. Every time you complete the dungeon, the crate gets pushed closer towards the end. With the weekly reset you can open your previous crate and get reward based on how far the crate was pushed.
Not sure what the crate contents would be, perhaps a selection of crest fragments?
This shouldn’t replace M+, just an additional fun PvE mode with a more focused, yet optional end-game challenge. Could always add a scoring mechanic, but that’s up to the community to start with 