Too slow unless you go first. Because when they flip ryko its gone, and once they flip spy they won't be dropping facedowns for a while. It would only provide relied against a manually flipped hamster.

Well, the main problem with White Ninja is that he's also a FLIP: Effect, thus you'd have to wait 1 turn if you intend to Flip Summon it and attack with it. You'd be better off with Nobleman of Crossout or Shield Crush in that case.

Blue have you tried any of the other suggestions? How'd they test?

So far, Light of Intervention has worked pretty well for me in some Decks. It's only too bad that other effects prevent them from being successful otherwise, or Mystic Swordsman LV4 (needing to be Set if you don't Special Summon it) or Search Striker (switches to Defense ala Goblin Attack Force if you use the effect) could've been effective uses. Can't exactly throw Marauding Captain into a Deck and expect it to work well constantly with MS LV4 either.