In essence, you target a subject, and cause all of reality to react negatively toward them. Time and space flux strangely in their presence; the elements 'run away from' and/or attack them; energy used BY them is weakened; energy used AGAINST them becomes stronger; their abilities go haywire; their own body seems compelled to work toward getting the subject killed, as his subconscious leads him into increasingly unlucky and unpleasant situations; destructive forces, like natural disasters and potential assailants (sentient or not) are strangely attracted to them; and it should go without saying, all sentient beings react to them with fear, distrust, hostility and nearly no empathy.
They are considered foreign enemy to all forces, energy, matter and life constrained within reality.
Counteracting this one will be very difficult, as it summons up numerous forces and effects to harm the subject, without direct control by the user. At least one of those forces is bound to be REALLY effective.
And just so you know, a version of this is also going to show up within the MythPowers. As in, a DIVINE version.
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)