The Last Great Mage is a Mythic ability added in Update 6.3. The update log describes it as the mana and spells of the mage of the Hero Party: ranged spell pressure. Its line is "The greatest joy of magic lies in searching for it."
Before you start
Equip Standless only when you are ready to use the Mage's Staff at the end. You can do the quest steps on another ability. You also want spare Grimoires if you plan to craft Blood Demon as well: the mage quest consumes 3, and the tome needs 1 more.
Quest order from the update log
- Talk to the Elven Mage near West Station and start her quest.
- She asks about Grimoires, then asks you to defeat Mimics. Defeat 3 Mimics and bring back 3 Grimoires.
- Antique Chests can be Mimics. The log lists chest spots at Dragon's Cavern, directly in front of Dragon's Cavern, the Prison, and near West Park.
- Return to the Elven Mage. She then asks you to defeat a fiend in the area.
- Defeat The Deceiver through Hecate's Slayer Quest. Demon NPCs for that quest spawn at Syrup Village and Floating Village. Lügner the Deceiver is summoned through the Slayer Quest.
- Craft a Magical Vessel. The log calls it Epic and craftable, and it does not print the ingredient list.
- Bring the Magical Vessel to the Elven Mage. She enchants it into an Enchanted Magical Vessel.
- Summon the Mirror Demon at the Boss Altar with the Enchanted Magical Vessel. One walkthrough instead says to use the vessel in Knight's Cavern. If the altar prompt is missing, check that second spot before you assume the item failed.
- Defeat the Mirror Demon. It drops an Ancient Grimoire.
- Return the Ancient Grimoire to the Elven Mage. She gives you the Mage's Staff.
- Equip Standless and use the Mage's Staff to unlock The Last Great Mage.
Mastery
The first mastery is separate from the unlock. Defeat the Mirror Demon again while The Last Great Mage is equipped. That unlocks the awakening move named The Slayer. Beating the boss before you own the ability does not complete this step.
Walkthroughs also describe an enhanced mode, Great Mage's Aura, opened when the mode meter is around 75% by pressing H. That meter step is from those walkthroughs, not from a sentence in the update-log text captured here.
Related achievements
Awaken with the ability once for The Last Great Mage achievement: 500,000 UCoins, the title The Slayer, and 30,000 UShards. Getting tricked by a Mimic is Novice Treasure Hunter. Getting tricked by a Mimic while using this ability is Competitive Treasure Hunter. Summoning and defeating the Mirror Demon is First Class Mage. Defeating the Deceiver is Demon Slayer.
The Struggle is a different fight: defeat the Mirror Demon with level 0 Standless, no trait, and no subpower. Any healing or help from someone else invalidates it, and bounties count as outside help. The reward is 10,000,000 UCoins, the title Losing isn't an option, 1,000,000 UShards, 50 Trait Rerolls, and 7 uF.