The short-range dual-wielder for the Viking camp is perhaps the simplest of the ninja types - no advanced maneuvers, deflects, or bleeds for this class. Instead, Berserkers leverage sheer speed, backed up with a number of uninterruptible attacks. Using the former to whittle down life and the latter for punishing deathblows, the berserker can take apart slower fighters while they're still sorting out their guard position.
In fact, a berserker is often better off with a counter-attack or dodge-attack than blocks and parries, as your speed allows you to beat other classes to the punch.
One important note on the uninterruptible stance- while you can't be knocked out of it, you can be damaged and even killed during it, so try to save them for when your opponent is stunned or off guard. Definitely mix them up with other attacks to avoid becoming predictable (which is to say, dead).
You'll also want to be wary of feints. While your speed lets you out-draw other classes most of the time, you can still be caught out by a feint-parry, leaving you achingly vulnerable to retribution.