|Featured In||Mistborn Era 1|
”I'm here to teach you how to fight. Not how to talk.—Gemmel about his teaching to Kelsier
Appearance and Personality
The aging man isn't completely sane, mutters to himself, and sometimes seems more beast than man. Gemmel thinks that Kelsier's forced smiles look creepy, and often stops talking in the middle of an argument. According to Kelsier, Gemmel doesn't understand humor, nor likes it when his pupil tries to take control.
Only three months after Kelsier escaped from the Pits of Hathsin, he and Gemmel visit Mantiz to infiltrate Keep Shezler. Along their way to the keep, they talk a little about Kelsier’s past, and all the while Gemmel keeps training his student, which includes attacking him. 
Upon reaching the keep, Gemmel goes up the roof to have a better view, killing some guards along the way. When he has taken a good look around and Kelsier has caught up to him, Gemmel throws his pupil off the roof. Once down again, they walk across the keep's grounds to a building that looks like a groundskeeping shed, and Gemmel again kills a pair of guards, not caring that it might reveal the two of them. In the shed, they find a stairway down, and Gemmel waves Kelsier to go first. 
In the basement, Kelsier starts sneaking through the room, but Gemmel comes in without any attempt at stealth. In the next room, they find half a dozen bound up skaa and Kelsier begins tending to them, but is interrupted when Antillius Shezler, the keep’s nobleman and also a Mistborn, shouts and shoots a coin at him. Kelsier manages to kill Shezler without any help from Gemmel, who sees this as a training opportunity. When Kelsier returns to the skaa captives, Gemmel is leafing through one of Shezler’s notebooks containing theories and superstitions about an Eleventh Metal. Kelsier takes this book before leaving, and Gemmel pockets a fork. 
”I wonder what I’ve unleashed upon the world by teaching you Allomancy. Of course, my trainer said the same thing about me.—Kelsier to Vin
Gemmel is Kelsier's mentor in the Allomantic arts. His training primarily focuses on the Pushing and Pulling metals, steel and iron respectively, but he also helps Kelsier to think like an Allomancer, for example by pressing him to have all eight basic metals burning constantly. He frequently places his pupil in life or death scenarios, like pushing him off a city wall. Although he often grumbles at Kelsier, Gemmel likes him more than his previous three apprentices, sometimes even showing some sign of respect for him.
It is very likely that Gemmel is Hemalurgically spiked. The two main reasons to assume this are that Gemmel hears a voice no one else hears that seems to tell him to kill everyone he meets (Ruin's voice), and that the mists aren't attracted to him like they are drawn to most Allomancers.
Through Ruin, Gemmel knew things he probably couldn't have figured out by himself, like certain aspects about Kelsier's past or where to find the Eleventh Metal. Ruin's influence also affects Gemmel's personality. At first sight, he just seems a madman, but a lot of what he says to Kelsier is very similar to Ruin's sayings. This applies especially to his answer on Kelsier's sarcastic question about the meaning of life.
”Don't know it. I think it's so we can die.—Gemmel's vision on the meaning of life
”The only point in creating something is to watch it die.—Ruin
- Gemmel met Zane once, but that meeting wasn't necessarily relevant.
- Gemmel was directed to find Kelsier, likely by Ruin.
- Fighting Kelsier to the death as a final piece of training seems like something Gemmel would do.
- The Eleventh Metal#
- The Final Empire chapter 3#
- The Final Empire chapter 27#
- The Final Empire chapter 5#
- The Final Empire chapter 8#
- The Alloy of Law Annotations
— Arcanum - 2015-11-30#
- The Hero of Ages chapter 57#
- /r/books AMA 2015
— Arcanum - 2015-08-01#
- Words of Radiance Omaha signing
— Arcanum - 2014-03-13#
- /r/books AMA 2015
— Arcanum - 2015-08-03#
|Mistborn Era 1|
The Final Empire · The Well of Ascension · The Hero of Ages
|Characters||Vin · Kelsier · Sazed · Elend Venture · Marsh · Spook · Breeze · Ham · Clubs · Dockson · Straff Venture · Zane · Ashweather Cett · Tindwyl · Allrianne Cett · TenSoon · Yomen · Quellion · The Lord Ruler · Alendi · Kwaan|
|Places||Final Empire · The Dominances · Luthadel · Kredik Shaw · Pits of Hathsin · Kandra Homeland · Urteau · Fadrex City · Tathingdwen|
|Ethnicities and Species||Skaa · Nobles · Terrismen · Inquisitors · Koloss · Kandra · Mistwraiths · Southern Scadrians|
|Organizations||Skaa rebellion · Steel Ministry · Keepers (the Synod) · Worldbringers|
|Mythology||The Deepness · Terris Prophecies · Well of Ascension|
|Era 1 books||Mistborn: The Final Empire · The Well of Ascension · The Hero of Ages |
(The Eleventh Metal · Mistborn: Secret History)
|Era 2 books||The Alloy of Law · Shadows of Self · The Bands of Mourning · The Lost Metal |
(Allomancer Jak and the Pits of Eltania)
|Shards||Preservation · Ruin · Harmony|
|History||Classical Scadrial · Final Empire · Catacendre · Elendel · Southern Scadrian|
|Magic||Metallic Arts (Allomancy, Feruchemy, Hemalurgy) · Metalborn · Mistborn · Misting · Savant · Ferring · Twinborn · Compounding · Atium · Lerasium · Ettmetal|
|Other Media||Mistborn Adventure Game · Mistborn: Birthright · Mistborn film · Mistborn: House War|