Blackflame is good at burning things

There was nothing in Lindon’s mind except his desire to push the enemy away from his partner. He shoved both hands forward, releasing the madra he’d stored up into a Striker technique.
If he could knock Gokren off-balance, even a weakened Orthos might be able to kill him. Maybe they could escape. But that assumed that Lindon’s pitiful Jade technique could even wound a Truegold.
An arm-thick bar of Blackflame madra streamed toward Sandviper Gokren, the technique dense and liquid smooth. The Truegold condensed a green spear out of madra, slamming his Forged weapon against the spike. Truegold Sandviper madra met Lindon’s Blackflame.
The dark fire washed over Gokren’s defense, taking his hand off at the wrist.
He stumbled back, eyes wide as he stared at the place where his hand used to be. Lindon stared, just as stunned. He had put everything he had into that Striker technique, to the degree that he was feeling dizzy from the strain on his spirit, but he had only hoped to take some pressure from Orthos. Even the Lowgold Sandvipers stepped back, turning their focus from the turtle to Lindon.

Blackflame (Cradle Book 3) [Lindon was actually a Lowgold and not a Jade, but that is still below Highgold, which is below Truegold, so there's still a big power difference]