Complex sentence: However, in 2146, following a software malfunction, the terraformers turned against their creators, and quickly overran and destroyed Earth's defenseless colonies, and, within a year, were ready to "Terraform" Earth.
Split into simpler sentences: However, in 2146, following a software malfunction, the Terraformer turned. They quickly devastated Earth's defenseless colonies, and, within a year, were ready to "Terraform" Earth.