Probabilitor the Annoying

If x is 1 or more, x in costs can be negative.
If x is 2 or more, x in costs can be a non-integer.
If x is 3 or more, x in costs can be imaginary.
If x is 4 or more, x in costs does not have to be
real.
Defender, Shroud, Invincible, cannot be exiled,
returned to hands, have its abilities altered,
and cannot be countered.