Replay Takeover
In Smash 6, when watching a replay the gamestate watched is stored in memory, allowing the player to pause, rewind, and start at a specific spot of the replay. The player may choose to take control of a character as if it was a live match at any point of the saved gamestate.
When doing this, Characters not controlled by a player will perform their inputs from the replay for a few seconds after takeover. Replay Gamestate is not overwritten while the player is doing this Replay Takeover.
Why It Matters
Replay Takeover helps the player recreate the exact scenario that occurred in a match and be able to test different possibilities.