I keep being told that it's just "Bad luck". Well, it's not bad luck if it happens all the time. And it does happen all the time.
The bosses in Love Island have Azumarill with hydro pump. Of course bliseey doesn't die from it, but the point of using flash (and hypnosis from mew right afterwards) is to bring in another pokemon which will buff up (Haxorus, cloyster, Bisharp, Slowbro etc) in 2 turns and swipe the rest of the team . If this works, the battle takes 15 rounds in total, and not 15 rounds per pokemon. These die from hydro pump, and it doesn't help when it hits all the time regardless of the accuracy drop.
What usually happens is this:
I bring in Blissey, use flash, and survive special attacks. Whe I m done, I bring in mew for hypnosis. When this works (lots of times it takes 3-4 turns), i switch to let's say Bisharp. Bisharp will use swords dance twice, and then swipe with sucker punch. But, most times it doesn't manage to use sucker punch twice, because once Azumarill wakes up, it hits despite having its accuracy lowered. If this happens with all three pokes I have brought in, then the battle is lost or I have to use revives.