The harshest lands in the world can still have people living there, and those with magical ability still need to be strong enough to survive the dangers.
This type of barbarian is able to cast spells, even while raging (though they can't concentrate on them and some spells end the rage when cast).
Slower in spell advancement than regular spellcasters, they can pick spells from a custom list that includes a mix of druid and cleric spells.