Couldn't "Change Environment" with the applicable modifiers be used for this?
Or, try this from one of Killer Shrike's characters whose power works 1) Mystic Anonymity: Major Transform 1d6 (Remove All Memory Of The Magus Maximus, Meeting Lord Arcane Again), Selective (+1/4), Personal Immunity (+1/4), Inherent (+1/4), Partial Transform (+1/2), AOE (One Hex; +1/2), Uncontrolled (+1/2), Reduced Endurance (0 END; +1/2), Persistent (+1/2), Affects Desol Any form of Desolidification (+1/2), Continuous (+1), BOECV (Mental Defense applies; +1), IPE, Hide effects of Power (Fully Invisible; +2), MegaScale (The Entire Dimension; +5), Penetrating (x10; +5) (281 Active Points)
Notes: Without constant exposure to the Magus Maximus, memory of his existance and role in events fades away. 0 2) Mystic Anonymity: Major Transform 1d6 (Remove All Record Of The Magus Maximus, Countermagic), Personal Immunity (+1/4), Inherent (+1/4), Partial Transform (+1/2), AOE (One Hex; +1/2), Uncontrolled (+1/2), Reduced Endurance (0 END; +1/2), Persistent (+1/2), Affects Desol Any form of Desolidification (+1/2), Continuous (+1), IPE, Hide effects of Power (Fully Invisible; +1), MegaScale (The Entire Dimension; +5), Penetrating (x10; +5) (247 Active Points)
Notes: All physical records of the Magus Maximus existance are erased / altered to conceal his existance and role in events. Admittedly, doing it this way gets really pricey really fast.