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If a move has less than 100% accuracy, say, 85%, and you use a move that increases your accuracy or decreases it, will the moves' accuracy change during the battle?
Basically, can stone edge get to 100% accuracy?
That answers my question. Also, if you look at the map, there are at least two mountains that look like they'll have ice types. On either side of the region. I expect a lot of new ice types.
Yes. You have a point. Not all pokemon with great abilities are useful. It could just be a gimmick. From the update in the ITT thread, it doesn't look like it has the stats to be an uber either.