You may pay WUBRG rather than pay this spell's mana cost. If you do, X is 5.
Bringer of Green Zenith's Twilight enters the battlefield with X +1/+1 counters on it. If X was 5 or greater, it enters with twice that many counters instead.
When bringer of Green Zenith's Twilight dies, shuffle it into its owner's library.
Near Mint - $39.600
Lightly Played - $31.700
Moderately Played - $27.800
Heavily Played - $23.800
Damaged - $19.800
Near Mint Spanish - $39.600
Lightly Played Spanish - $31.700
Moderately Played Spanish - $27.800
Heavily Played Spanish - $23.800
Damaged Spanish - $19.800