Olenna is the Crusader name that belonged to at least two women: a mistress and her apprentice.
Olenna was a Crusader who ventured into the Swamplands. Eventually, she encountered a human figure adorned in demonic armor with magical spikes, hidden in unnatural fog. Olenna's trial grew more challenging each day, as the thorned figure continued to attack her from the mists.
After direct combat ensued, the figure attempted to impale Olenna with a dagger, but the sacred armor she wore shattered the blade. The Crusader subdued the attacker with ease due to the opening, and realized that it was a young girl, no older than twelve — a Vizjerei apprentice whose will was bound by the magic of her mentors. Upon defeat, the armor released its grip on her mind and attempted to kill her, turning its spikes inwards. Olenna took pity on the girl, and with the power of the Light, saved her from being impaled.
Eventually the girl recovered, her mind and body healed by the holy rituals, and wished for the cursed armor to be destroyed. However, Olenna decided to purify it instead, and with some effort, succeeded. She made the girl her apprentice, and together, they marched north.
Olenna's blessed armor and name eventually were passed down to her apprentice, who bore them with pride along with her own cleansed armor of the invoker. She soon came to be known under a different moniker than Olenna however.