Attacker base camps
1. Works with either 9x9 or 11x11

2. White wins when the king reaches an edge square other than a square where an attacker starts. These will be known as basecamps. (The squares where the attacker start) A 9x9 and 11x11 both have 16 victory squares.

3. Base camps act just like a hostile throne but for all peices. Once vacated by an attacker no one can land on any of these squares.

4. The throne is hostile. The throne isn't hostile to white when the king is on the throne. Once the king leaves a white piece can be captured against the throne.

5. The king can capture. The king is captured in the same as his men. This means that a king next to a base camp can be captured by one single piece.

6. A king on the throne must be surrounded on all four sides and a king adjacent to the throne must be surrounded by three sides, much like here on this site.

This variant makes for a quick and bloody contest. I found the rules on an IOS app on my phone , it seems fairly balanced but I've only played against a computer.