I'm thinking of making my Kyogre more like my brother's. So: Water Spout, Rest, Sleep Talk, and Ice Beam/Thunder. The question is, should I get Ice Beam or Thunder (or something else? likely not but still an option.)
Ice Beam: Deals with Grass types and Dragon types. Has higher PP. 10% chance to freeze. 100% accuracy.
Thunder: Thanks to Drizzle has 100% accuracy and a 25% chance to break through Protect and Detect. However, if another weather effect comes into play or if Drizzle is cancelled, Thunder will have only 70% accuracy. Thunder also does more damage than Ice Beam at 120 base power, and also has a 30% chance to paralyze. It also can deal with other Water types.