Innermost energon

Innermost energon is a part of a Transformer's body from the IDW portion of the Generation 1 continuity family.

Innermost energon is a Transformer's "core reserve" of power, the energon around their spark casing that remains there no matter what changes are done to the rest of the body. It is extremely potent.

Fiction

IDW Generation 1 continuity

When his fellow Duobot Ore was killed, Shock marked his passing in traditional form, with a vial of innermost energon along with some poetical remarks. The Chaos of Warm Things

Krok's band of Decepticon Scavengers hoped to find some innermost energon among the many scattered corpses on the battlefield world of Clemency. Krok commented that just half a gallon would be enough to power their ship, the Weak Anthropic Principle, for months. Rules of Disengagement After Flywheels was killed by the D.J.D., the survivors of the group speculated that there might be enough innermost energon for a sip each. Who's Afraid of the DJD?

Offering someone part of your innermost energon showed how important they were to you, and that you cared for them very much. Many crew members on the Lost Light left vials of their energon with Rewind after he was injured in battle, and Tailgate tried to do the same with Cyclonus. The fuel he decanted was green, Before & After his energon having curdled as a result of undetected cybercrosis. The Fecund Moon