Complex sentence: Lady Diabolyn is helped by the Goons, mischievous creatures led by Dweedle (voiced by Billy Barty); they were formerly Diabolyn's guards until they gained their monstrous appearances by the Spectres upon opening the urn containing them when Diabolyn told them not to.
Split into simpler sentences: Lady Diabolyn is helped by the Goons, mischievous creatures led by Dweedle (voiced by Billy Barty). They were formerly Diabolyn's guards until they gained their monstrous appearances by the Spectres upon opening the urn containing them when Diabolyn told them not to.