Brush

If this is the first battlefield that player has scored, they'll draw 1 and the game will continue with both players at 8 points.

If you replace Aspirant’s Climb with Brush via Green Father’s conquer or hold effect, the Victory Score will change immediately as the passive ability of Aspirant’s Climb is no longer in effect, bringing both players to the Victory Score simultaneously. Rules 323.1. and 467. define winning the game as happening during a cleanup when one player has points greater than or equal to the Victory Score and greater than any opponent. If both players are at 8 points, they have not fulfilled both requirements for winning the game. They will need to score additional points in order to win. When they do so, 466.1.b. says “when a player tries to gain a point through a Score, and their current point total is one point from the Victory Score for their Mode of Play or higher , do the following: …” If the point is from Conquering, they will draw 1 instead of gaining the point unless they have scored each battlefield that turn. In effect, every point at or above the Victory Score becomes the final point.

The Brush token will cease to exist. When swapping back, a player can choose to swap back to any object that was replaced, including the original battlefield.

This is because a replacing game object inherits all of the statuses and conditions of the game object it replaced, per 438.1. A game object can be instructed to “swap back”; the token stops existing and the original card is returned to the space that the token occupied, inheriting all its current effects and statuses per rule 438.7.b. “All of the effects and statuses” includes not only temporary effects applied to the battlefield, but also the relationship between replaced and replacing battlefields.