Jin-Gitaxias, Progression Lord

When Jin-Gitaxias, Progression Lord enters the battlefield, choose a color.
Whenever you cast a spell of the chosen color,
draw a card and create a 1/1 blue Phyrexian
creature token.
Whenever an opponent casts a spell that isn't the chosen color, that player discards and mills X
cards. Where X is equal to that spells mana value.