Jonah Charlson

Jonah Charlson is one half of the duo of criminal mercenaries known as the Bomb Brothers, who illegally create and plant technomantic incendiary devices for paying clients.

Traits
It is presumed that one of the Bomb Brothers is a technomancer and the other is a pyromancer, thus allowing them to create their bombs between the two of them without any outside assistance, but this is not explicitly stated.

It is most likely that Jonah is the technomancer, since he is the one that confirms when the bomb is operational.

Outside of creating and planting explosives, despite their criminal lifestyle, neither of them are comfortable with violence.

They're also not actually brothers.

The Good, the Bad and the Mediochre
The Bomb Brothers are hired by the Sapphire Smuggling Syndicate to destroy a railway station in order to prevent Mediochre from reaching the Cairngorms by train. Unbeknownst to them, Mediochre anticipates this and sends Forthan Forth to prevent them from setting their bomb off, which he seemingly achieves by threatening them with a katana.

It is unknown what became of them after this, although it can be presumed that Forthan probably had them arrested.