You'll never found a more loyal Decepticon to the cause than Soundwave. An extremely and unusually powerful telepathic Outlier, Soundwave fell under Megatron's sway and became dedicated to him and his cause to create a galaxy built on the concept of Cybertronian equality. When Megatron defected to the Autobots, Soundwave endorsed Galvatron's taking over as Decepticon leader in the name of peace only for Galvatron to try and create a new empire. Forming an alliance with Optimus Prime, the two overthrew the tyrant and now work together to try and uplift Earth into the cosmic community.
While he first viewed humans as nothing more than short lived and expendable drones, he's slowly starting to get better around them. Slowly. He also hates Rom.
Aboard the Sanctuary Station, Soundwave was blackmailed by Optimus Prime into service to try and stop Galvatron. Though Soundwave followed through on the alliance, he held no love for Optimus until he witnessed the Prime raise Metrotitan.
Months later, Soundwave's telepathy allowed him to hear the explosion of Ore-13 being primed beneath Mount Olympus but doubted the crew of Autobot City would be able to evacuate in time should their own Ore-13 stockpile detonate. Nonetheless, the explosion was enough for the successors of the Earth Defense Command, G.I. Joe to declare open war on the Cybertronians. He accompanied Optimus, Windblade, and Victorion to Portland, Oregon to confront the humans. Thoroughly unimpressed by the humans' lack of rationality or their weapons, he launched a massive EMP attack that deactivated all their equipment (and unknowingly saved himself from a more lethal version of the old EDC mindbomb), warning the humans that he could have made the attack lethal to them as well. The battle was interrupted by an unknown silver alien who killed four Joes. When the Cybertronians fell back to pursue the alien, Soundwave restored the humans telecommunications so that they could tend to their wounded. They tracked the alien to the Umpqua National Forest, where it managed to flip Optimus Prime before the other Cybertronians surrounded it. The alien managed to punch Soundwave in the face before it was soundly defeated and encouraged at gunpoint by Optimus to speak. The alien introduced itself as Rom and explained his mission to hunt down the Dire Wraiths who had taken an interest in the power of Ore-13. Soundwave agreed with Windblade that Micronus Prime's realm of Microspace was their priority as Aileron had confirmed the Energon was disappearing into another universe. Before the debate could continue more, the nearby spacebridge activated, and Rom began sending many Ore-13 crystals to Microspace. In doing so, the Space Knight was jeopardizing that universe before Optimus made him see reason. Soundwave then told Rom that he sympathized with placing expediency over morality as he placed the Space Knight in stasis cuffs.
When Arcee began fighting a group of intruders, Soundwave broke it up with a sonic attack. When the Dire Wraiths, bolstered by M.A.S.K. forces, attacked, Soundwave was attacked by the humans before shaking them off to aid Optimus from a Wraith assault. When the spacebridge activated, Soundwave tried to shut it down only for Baron Karza to emerge and absorb all the Wraiths into himself. When G.I. Joe arrived, Soundwave caught the falling Dragonfly of Mainframe and Mayday and apologized to the former for what happened in New York City. Mainframe did not accept it but understood that there were more pressing matters at hand. Realizing that he could communicate with everyone through Ancient Cybertronian, Soundwave formulated a plan to use Rom, Matt Trakker, the Micronauts and Mainframe as buffers while he calculated a counter frequency against the detonation of the Ore-13, though this would destroy the spacebridge. When it the portal sucked Karza back inside and detonated, Soundwave shielded Mainframe inside his chest compartment though losing both his arms in the process. He returned to the lower levels of Autobot City in time to see Optimus announce his intent to work with the humans rather than around them.
When Rom flew off, Soundwave expressed his distrust of the Knight and displeasure of his methods before Optimus cut him off stating they had more urgent problems.
- Soundwave (G1) at the TFWiki