Seeing as one of Ho-oH's biggest counters is Zekrom, I would suggest Earth Power over weather ball. I'm not even sure what the Water type move in rain would be doing, or the Rock type in sand. I think even with a +1, Ho-Oh could still be relatively easily phased by Lugia, and could probably not Weather a choice scarf water spout from Kyogre. A CM set in general seems fairly prone to revenge killing...
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