One of my favorite classes, it is extremely fun to play as the Berserker because they can do a ton of damage and, after dropping their holy shield (something the Paladin wields), they can focus on sheer damage and health.

The Berserker has plenty life steal which gives them very good sustain in battles, even when dealing with multiple enemies which can be quite powerful. They also have high defense because they originally are Warriors, so they can't be squishy!

With the Berserker you can tank a little, but not as much as you could with the Paladin, because they are not built around that. However, depending on the situation, the Life Steal could be enough to sustain all of the damage you take, but most of the time in multiplayer instances you will find Paladins to take on the tanking burden.

Skills:

Sword Strike: Crushes the ground with the greatsword and causes a shockwave which damages the enemies within the target area. The caster is also significantly healed depending on the damage caused by Sword Strike.
Enhanced Rage Burst: Deals damage to nearby enemies, significantly increasing the damage dealt by the caster, while also increasing their resistances to negative status.
Bladestorm: Wields the greatsword into a storm of destructive force, dealing great damage to the enemies in range.

Overall, the Berserker is built around damage, with mild defense. The more damage you have and deal with Sword Strike, the more you heal. So especially when fighting multiple enemies, you will heal like crazy!