It also ignores Lightningrod, Volt Absorb, Motor Drive, Wonder Guard, Solid Rock, Filter (although Filter is mostly irrelevant because it's limited to Mr. Mime), Flower Gift, Friend Guard, Sand Veil, Snow Cloak, the crit-blocking abilities, Shield Dust, and
a bunch of other abilities less relevant to Ampharos. Mold Breaker makes it particularly potent in Doubles, as its Thunderbolts will smash Thundurus-T and do good damage to Manectric and they can't be redirected.*
You're posting this in the wrong place though - this question belongs in the
Simple Questions, Simple Answers thread in Uncharted Territory. Smogon Metagames (with the exception of some of Other Metagames) is a place for discussing Black and White competitive battling.
*Don't quote me on that, I may be mistaken.