Mercenaries are models that players can hire on a per-mission basis. They are not formally part of your strike force, and unlike your regular models they will not accrue experience or learn new skills. They are costly but powerful, and can be taken along for individual missions where you need an extra boost of combat ability or expertise. Sometimes the only way to turn a losing streak around is to hire a trenchcoat badass that looks a bit like the Predator. Blaine's stat card is below:
As you can see, Blaine hits like a truck. His shooting is nothing to speak of but in close combat he will have Brawler and 3+ Fight with an AP2 weapon. He's not Fast but Scout will allow him to deploy closer to the enemy. The main reason he will reach the enemy lines reliably is because of his exceptional toughness: Blaine has 4+ Survive with Armour 1 and Really Tough. This makes him just as hard to take down as a Stage 1 Plague (arguable harder due to his smaller size) with the added benefit of not being Slow like the Stage 1 is.
You can rest assured I'll be including this close combat beast with my Marauders the moment I feel my Mawbeasts are not quite slashy enough. With that said, there's no reason you can't hire Blaine for your missions, (or alternatively a proxied not-Blaine if both players want to hire the same mercenary for the same mission).
