Trix, the Wild Mage

MAGIC! — {g/u}{r/g}{u/r}{1}: Roll a d20. Exile cards
from the top of your library until you exile an
instant or sorcery with converted mana cost X.
Cast it without paying the mana cost. Put the
exiled cards at the botom of the library in a
random order.
1-9 | Roll a d6. X is equal to the result.
10-19 | Roll a d8. X is equal to the result.
20 | Roll a d10. X is equal to the result.