World Ultimatum

If X is equal to 3 minus the two-thirds the number of Gods in play(rounded 1: to the nearest whole number 2: down) minus the number of cards named World Ultimatum(minimum 0), search your library for up to (X less than 4)God cards. You may cast them. They cost {2} less to cast this way.
If {w}{u}{b}{r}{g} was cast on World Ultimatum, search your library for up to 4 cards named World Tree and put them on the battlefield tapped.
Shuffle your library.