Does Scion of Nothingness's Echo count Wraethe cards in your draw pile, and does it recalculate later?

Question

Accepted Answer

Echo counts only Wraethe cards in your discard pile, and purchased cards go there too. The bonus is gained when you play the card, and a later change to the pile does not retrigger it that turn.

Shards of Infinity

Does Scion of Nothingness's Echo count Wraethe cards in your draw pile, and does it recalculate later?