The six cards work, but only 6 cards with skill that aren’t used that much isn’t that exciting as you don’t always get them and you can only have 1.
Perhaps if gaining a stone granted you an immediate roll on a table that allows player to:
- Teleport: May move model anywhere on the table
- Gain Arrows: May immediately win D3 Arrows (1-2: 1, 3-4: 2, 5-6: 3)
- Curse: May destroy one danger on the table (excluding monkey king and fogs)
- Free turn: May take a free turn
- Steal: May steal any tile from one nominated player.
- Ghost: May ignore the next Danger.
They could be called Songs of the Forest.
When ever a Kodame finds a stone, the forest sings a song granting the champion a special favor.