I have a Soulmate!AU TFPish with IWD elements idea where the human OC/SI has been hearing their soulmate hum and sing to them since babyhood. They even became an acomplished musician. Their soulmate, who had such a magnificent rich bass, would even play improvisational echo games with them with a particular song. But with a diffrent one he always ignored them.
Then the Deceptacons attack their city. The human is shocked and horrified. Soundwave was blaring the Deceptacon Battle anthem. It was their song. They give up their instrument and stop singing. They join up with team prime and throw themselves into the war. They become a munitions specialist, basically sharing a braincell with Wheeljack the Wrecker. Ok they become a Wrecker in their own right.
Eventualy Jazz pokes and pesters them into revealing why they don't do music. Miko plays the chords the soulmate transcribes for Jazz. Jazz wishes his worst fears weren't confirmed when Miko mangles the opening of the Empeyrien Suite. Jazz just got word the DJD's answering Megatron's call the same way he answered OP's to come to Earth.
Soulmate has orders from OP to reveal herself to her Soulmate if she's Endangered by the djd. One the shock might give her window to escape. If it doesn't Tarn's at least likely to kill his soulmate quickly.
Tarn and his mechs are searching an abandoned booby trapped base when he hears from the speakers and in his head a familiar voice rough with disuse, heavy with venom. The shock of is amplified by the words he now understands "🎼🎵I am flesh and I am bone...🎵" His sparkmate who he assumed to be a sparkling or protoform is a squishy. Worse when he finally catches sight of them and the badge of the Wreckers proudly tattooed to their shoulder. Nuke or not he and his team got very scorched and exploded. To add insult to injury while carrying his sparkmate out of there one last blast went off covering him, his team, and his reluctant sparkmate in a sickly unicorn vomit of glitter.
This is the song soulmate dumps on Tarn