Center of the Universe

Whenever a star permanent you control enters
the battlefield, add one mana of any of its colors,
it is not lost between steps.
Journy Beyond - {w}{w}{u}{u}{b}{b}{r}{r}{g}{g} {t} -
Search your library for a card, exile it under
Center of the Universe.
When Center of the Universe has 5 or more cards
exiled under it, transform it.
This card can be your commander. (Version 1)
X'Thuloth, Edge of Reality 20/20 ->