Each time you successfully deal sneak attack damage with an attack on a creature that is not a construct, you steal a portion of the target's soul, gaining a number of Soul Shards equal to the number of sneak attack dice you rolled.

You can have a maximum number of Soul Shards equal to half your WIS score. After each long rest, you retain half the amount of Soul Shards you had before the long rest, should you had only 1 Shard at the beginning of the long rest, you finish your rest with 0.

At 13th level, the maximum number of Soul Shards you can have becomes equal to your full WIS score.