Complex sentence: Ellefson alleged that Mustaine short-changed him on profits and backed out of a deal to turn Megadeth over to him when the group disbanded in 2002, as well as locking him out of merchandise and publishing royalties.
Split into simpler sentences: Ellefson alleged that Mustaine short-changed him on profits and backed out of a deal to turn Megadeth over to him when the group disbanded in 2002. Ellefson also accused Mustaine of locking him out of merchandise and publishing royalties.