"With the All Spark gone, we cannot return life to our planet." Optimus Prime, 2007. So what made Sentinel believe he could do it with seven billion slaves? The only thing even close to the divine power of the AllSpark was the Matrix of Leadership, which he rejected and later had blown up by Starscream (when the Autobots left). I can accept the new girl after the ROTF love scene, Soundwave's time-travel (according to the comics), and Sam's non-publicity status after being manhunted, but ignoring a plot device of two films is IMO pushing it.