Complex sentence: When Orm succeeds in capturing Aquaman and becomes "Ocean Master," Black Manta betrays and imprisons him, planning to use a machine to destroy and plunder Atlantis, but was stopped by Aquaman, Ocean Master, and Batman.
Split into simpler sentences: When Orm succeeds in capturing Aquaman and becomes "Ocean Master", Black Manta betrays him and imprisons him. He plans to use a machine to destroy and plunder Atlantis, but was stopped by Aquaman, Ocean Master, and Batman.