Oh, that's god, means that Cloyster doesn't have to risk being forced to switch when attacking.Read somewhere that Cursed Body has a 33.3 % chance to work, but that's not confirmed yet, I think - but it's sure that it doesn't work all the time.
Although Desukan will probably force a switch too, removing Skill Link would make Cloyster RNG hell until is swaps out.
Bulk isn't very kind to Cloyster.