- Multiply two stones in your hand together.
- Cannot be discarded.
- Cannot be placed.
- Can be placed on holes outside the board.
- Remove one space on the board in the same row or column.
- Siphon your opponent's energy.
- A: Equals the average of all cards in hand.
- Swap the effects of two primes (You must have both of these primes in your deck or hand) for the remainder of this battle.
- Tiles on opposite sides of this stone are considered adjacent.
- Can be taken off of the board and placed back in your hand.
Viewing post in Additional prime effect ideas thread
Surely the opponent would be smart enough to never steal such a stone... you'd need to expand the effect to be something like "whenever your opponent alters your hand, this stone is moved to their hand instead", so if your opponent uses something like 37 or 61 or 89 then instead this stone gets moved to their hand.