(1) I love Entropy and its flavour.
(2) Despite (1), I don't think the game needs more randomized effects to be added. Random, while fun, is toxic to the skill.
(3) Still, if this cards has to be, I think it should cost the same price than Pandemonium, or even a little less for the Upped version. It is rare to see an Upped mutation failing; most of the time, it is a buff. So it means that this card, while controlled by its caster, has high chances to buff your opponent's army.
(4) Based on (2), may I suggest to remove a random component? Maybe just propose a mass mutation that *can* affect all creatures on the field and remove the "tower and pendulums = number of targets" part.