"What is your name?"
"Lille."
Optimus Prime sat on the production line of an abandoned factory, with a green-and-yellow painted Autobot beside him, welding and repairing his wounds.
[Name: Ratchet]
[Description: The Autobot "doctor."]
"Boss, you're badly injured..."
The battle was over, the Decepticons fled, Optimus Prime... was severely wounded, his surface covered in dents from plasma guns and bullets, the worst being the gash from Megatron's final sneak attack.
In human structural terms, this axe cleaved down from the right shoulder, penetrating the chest, you could even see the glistening core through the opening.
Although Transformers are incredibly resilient, they are significantly different from robots in the conventional sense.
When they are injured, they require repairs. If metal with similar atomic structures is available as a supplement, the wear is minimal. If not, they must rely on "doctors" or themselves to convert metal into the same type for repairs.