Baykeep Leviadrya

Conduit (When you cast your first conduit spell each game, its color becomes your conduit color.)
Baykeep Leviadrya has dreamwalk as long as your conduit color is blue. (It can't be
blocked by untapped creatures. Instead, tapped
creatures can block it. Tapped creatures that
block don't untap during their controller's
next untap step.)