【How-to】Is there a trick to catching thundurus

Giratina can attack only 30 times before it starts using Struggle, which knocks off a quarter of its health each time it is used. Turns of sleep, freeze, flinch, and full paralysis do not count toward this; if you see “GIRATINA used (move)!”, then it has attacked. Remember to save before you engage Giratina in battle!