Tzeentch, Changer of Ways

Tzeentch, Changer of Ways cannot be countered
Indestructible, Hexproof
When an opponent casts their first spell per turn, counter it instead then draw cards equal to target spells converted mana cost. If the target spell has
a converted mana cost of {4} or higher you may
copy target spell and cast it without paying its
mana cost