Just wanted to share my findings.
Not an obvious thing, but tiger barb is
insane. It kinda lies on the surface but is concealed at the same time.
It all comes down to the
Tiger's Bloodlust ability, which is:
Lash out to attack up to 3 enemies at once. They each take half the damage your weapon usually deals and start to Bleed.Pretty simple, right? But what this ability does is it gives
Cleave to the weapons that do not suppose to have it. How useful is that? I did some testing with different weapons and those are my results:
- Nature's Snare. Procs
Entangle on every enemy you hit with this action.
It can proc even if you miss. You can ensnare groups of enemies every turn, giving your allies advantage
and restraining them, and adding 1d6 damage. Very good.
- Sparky Points. Procs 2
lightning charges from every enemy hit by the cleave. Then +1 (or 1d8) lightning damage is added both on the cleave
and the bleeding it causes. Very, very good DPS.
- Shattered Flail. 1d6 healing procs from every enemy you hit with a cleave. On its own this is not very impressive, because the damage is pathetically low, but it shines differently, when combined with...
- Loviatar's Scourge. A necrotic
1d6 AOE procs on every enemy hit by a cleave, which results into a massacre. It deals a ton of damage to not only the enemies (or allies) you hit with a cleave, but also those that are just standing near. Just look at a combat log screenshot below to get a grasp of its potential:
The drawback is self damage - it can get pretty high at times. Here comes the
Shattered Flail and the dual-wielder perk, which allows you to heal back all HP lost to the scourge. Or, if you want another lvl4 feat, the Glowing Shield and an Absolute's Amulet could work too.
- Gloves of Power. Bane procs on every enemy you hit with a cleave. A very potent debuff and it can be combined with any of the above mentioned weapons.
Just wanted to share those impressions on a seemingly not that useful subclass, which turned to be a blast in my playthrough.

I'd be happy to hear any other thoughts on building a barbarian, feel free to share.