Olberic Eisenberg is a former knight from the fallen kingdom of Hornburg. After his king was killed and the kingdom fell, he wandered the lands as a sellsword, which brought him to live temporarily in a Highlands village named Cobbleston. It is here that he is seen training the men of the village to help defend it from bandits. Olberic has a strong sense of justice, as seen when helping protect those around him.
Olberic's Path Action is called Challenge and it is the same as H'aanit's Provoke. You will be able to duel a NPC and should you win, the NPC will be knocked out on the ground after the fact. Outside of story bits, you will want to do this to get inside some buildings that NPC might be guarding, plus there are some instances of NPCs dropping some powerful equipment. Unlike H'aanit, Olberic has full range of his abilities, including basic attacks, although he will sometimes need to be specific levels in order to Challenge certain NPCs (similar to Alfyn's Inquire).
Olberic's Talent, Bolster Defense, is very simple, as it allows him to use Boost on the Defend command in battle. This essentially makes Olberic the best tank in the game, especially with some of the Warrior's skills, since you can get the enemies to attack you with Incite and use a boosted Defend on the next turn.