This mercenary is a strange fellow, but a fun troll to have around. He is the Ironmonger, a 'jack marshal/mechanic that a handful of factions can hire, including trolls. As soon as he was released I knew he had to be in my troll army since I love warjacks and I have a strong affection towards trolls.
Apart from weirding out my opponent when I deploy merc 'jacks beside my dire trolls, he has been really solid on the tabletop. With two heavy 'jacks under his control, I can send him off to clear a zone or hold an objective. Due to his repair ability, his 'jacks are almost as resilient as the other trolls and hit just as hard. Although his awesomeness might just be due to the fact that my dice love him.