Yep, Dream Mastery blends seamlessly to every other feature to the game, so it'll be accessible as your second mastery the second you gain immortal throne.
[color="DeepSkyBlue"]Listen up maggots, Mr. Popo's 'bout to teach you the pecking order.
It goes you, the dirt, the worms inside of the dirt, Popo's stool, Kami, then Popo.
~Mr. Popo, Dragonball Z Abridged[/color]