If he can show that the bank accounts that he had all these millions in are legitimate and then explain why he didnt include them in his SALN disclosure then there will be no need or threats of an impeachment.
You cant really promise to route out corruption before proving that you,yourself and your accounts are clean.
Its also not much good answering the question "where did the 211 Million PHP go" and just answer that it all went on "Happy happy"!!!!

He will have to come up with something better then that!!! LoL.