I have played furyshaper/ancient, berserker/ ancient and corpse eater/ancient and they all are really fun to play.
Because blood thirst triggers with dot spells (plague of insects, infestetation of maggots, insect swarm) you will have a lot of time with zero recovery and also good healing spells( moonwell etc) and storm spells which helps the squishiness of barbarians. Spirit frenzy also lowers fortitude which helps you to land your spells.
Stag garnage (community patch) and barbarian carnage stacks which is also nice or you could go melee with whispers of the endless path and use taste of hunt aoe dot.
This is all borrowed from @Boeroer posts so credit where it belongs.