The easiest place to charm a Black Bear is at the beginning of the Ice Caves of Sorrow mission. Multiple bears will spawn near the starting point, and one should be close enough to pull away from the nearby enemies.
The Brutal Mauling skill takes longer than a regular attack but deals no additional damage, giving the Black Bear a lower damage output compared to other pets. However, this attack skill allows the bear to trigger effects that require an attack skill, such as those provided by certain Paragonchants that affect all allies.
Taming a Black Bear in Pre-Searing is difficult, but not impossible. It requires two players, the one charming the bear and a decoy.
The decoy must move in first to take the bear's aggro. The charmer should stand with the bear at the limit of spell range.
Wait for the bear to use Brutal Mauling, which it will use on every fourth attack. Right as it begins activating the skill, the charmer activates Charm Animal and the decoy begins running away.
When the bear finishes Brutal Mauling, it will chase after the decoy, taking it far enough away that Breaking Charm will be unable to affect the charmer.