Thorn of Amethyst

Noncreature spells cost {1} more to cast.

Gaddock Teeg

Noncreature spells with mana value 4 or greater can't be cast.
Noncreature spells with {X} in their mana costs can't be cast.

Yargle and Multani

Yargle, Glutton of Urborg

Jasmine Boreal

Jasmine Boreal of the Seven

{T}: Add {G}{W}. Spend this mana only to cast creature spells with no abilities.
Creatures you control with no abilities can't be blocked by creatures with abilities.