Marshal Law
To explain the build for you Penchant -
Basically an armoured tank to be able to move about the battlefield to repair men and equipment. The character has considerable in-combat medical abilities if you're familiar with the healer's hands feat and treat deadly wounds combo. The blacksmith class provides good repair abilities for guns that get the broken condition or otherwise, if there's vehicles involved for example. The blacksmith also has useful daily group buffing abilities which can be seen under the Maintenance heading of the class (all spheres links are above).
Offensively Marshall has a reasonably grunty alchemy grenade capability but that is highly ammunition restricted and has other issues, it's not instantaneous and if you're up against somebody with evasion it's worthless (see Other Notes in the character sheet for details). He's a specialist in taking out enemy weapons as a base ability of the blacksmith class, if troops are pinned down by a heavy machine gun he looks to take out the machine gun rather than the gunners. The key point with the build though is with his grenade launching crossbow and to have a bit of alchemy fun - to be able to shoot tanglefoot bags at range and so forth.
One specific ability that could want noting as different from standard 1e is the active shield sphere ability to redirect missed attacks back at enemies at -2 to hit which costs an AoO to use.
Useful side abilities are his high tracking skill level and the sphere's scout ability to identify creature weaknesses without resort to a knowledge skill.
So, yeah, tried to stay on setting theme with the class, and with the group support abilities avoid any over-the-top damage output combos of spheres.