I feel like combining this concept with the X-stone could be problematic. If you have 100 energy and play a single 1/97 you will then have 9699/97 energy and then playing the X-stone would require the game to figure out that 9699/97 = 3 x 53 x 61 x 97^-1. But if you instead play a single 1/97 and a single 1/89 and then the X-stone, the game will have to prime factorize 863114/8633 = 2 * 7 * 89^-1 * 97^-1 * 61651