This has been Megatron's plan all along. Soundwave's systems were designed to grow and evolve when exposed to the Key; eventually, Sari will unwittingly upgrade him into a suitable body for Megatron himself. Bulkhead begins to see signs of Soundwave's evolving nature—"Did that thing just move by itself?"—but no one believes him. Megatron successfully uses Soundwave's weaponry and voice-modulation systems to make both Sari and the Autobots think Bulkhead is erratic, jealous, and dishonest.