Elder Spellskite

{x}{x}{p/u}: you lose X life. Split second. Splice onto
noncreature spell an opponent controls. As long
as this ability is on the stack, players can't cast spells
or activate abilities that aren't mana abilities. You
may activate this ability only if a noncreature spell
an opponents control is on the stack. When you do,
add this ability's effects to that spell. This ability has
no effect on you.