Wile trying out a Roid deck [vs AI shadoll/artifact], i set Gyroid, then the AI, with 2 cards [Shadoll Winda and some 2300 atk Synchro] attacked it to reveal it, not destroy it because of Gyroids effect, and from there on it it just wouldn't attack Gyroid, even with a full monster zone with 1000+ monsters. i set other cards and it would destroy them fine, but i just kept Gyroid out in defense and it stalled so much it decked itself and i won by that condition.