Forum:Thunder King Rai-Oh. Effect ruling

ALright, this has been tricking me up. You attack a face down "Apprentice Magician" while "Thunder King Rai-Oh" is on the field. Can you negate the special summoning of a monster from thee effect of the Apprentice Magician? If not, why not?

68.194.159.185 06:00, 30 August 2009 (UTC) --> Moutou, Atemu