Timeline Reset

At the end of a creature's turn, break the flow of time and force it to relive the past 6 seconds.

• The creature goes back to the space it occupied at the start of its turn
• Any damage inflicted, healed; and resources spent (like spell slots or abilities) are undone and recovered
• Any reactions caused by this creature before the end of its turn are also undone 
• Any change to the state of the world caused directly by the creature is reverted

Immediately after, the creature is forced to take its turn again and must try to redo all of its actions, movements and additional actions in the undone turn.

• Other creatures may choose to or not to react the way they did originally
• If the creature is hostile to you, it must do all attack rolls and skill checks with disadvantage and its targets do saving throws with advantage
• If the creature is voluntary, is does all attack rolls and skill checks with advantage and its targets do saving throws with disadvantage

If somehow, circumstances change in a manner where an action is no longer possible (for example target is no longer there or a movement is no longer possible), the action is lost and skipped.