Treasure Chest and Chest Key System, which was discontinued with the Infinity Keys's release.
It is also not a simple replacement for the old system, but instead a complete revamp, including an all-new rewards list.
The Infinity Chest is located at the Soul Room (accessed with the ::soulroom command).
Opening the chest will deposit the prize directly into your bank.
The drops list for the Infinity Chest hasn't been released. The following is as complete a list as possible from in-game testing, and will be added to continuously as more rewards are observed. If you receive a reward which is not on this list, please contact a wiki editor!! All reward rates are unknown.