So... River Kelpie. I'm tinkering with two directions.
1) U/G - pushes card draw and a little "hand size matters" with Lorescale Coatl and leading up Overbeing of Myth. Little flashback, retrace, and unearth.
2) U/B - some retrace here, too, but it also focuses on Haakon and his almost unfair interaction with Nameless Inversion. More control-ish.