Simon

Before Beastman War arc
Simon was born in Jeeha Village, one of many subterranean civilizations on Planet Earth in the far future. Unlike other villages, Jeeha Village had supplies of fresh water, animals (Mole pigs) for food and electric generators for light. In spite of this, there was an ever-present threat of cave-ins from earthquakes, so the village chief employs diggers from the energetic and maneuverable youth to create new routes for the city to expand. Simon became one of them, and quickly distinguishes himself as one of the best diggers. At age seven, Simon's parents were killed before his eyes in a cave-in during an earthquake. The incident traumatized him and gave him a phobia for earthquakes. Simon then devoted his entire existence to his job, earning him the scorn from his peers. Only Kamina, the local gang leader and juvenile delinquent, reached out to Simon. Kamina "recruited" Simon into "Team Gurren" by dragging him along on outrageous schemes to escape Jeeha Village to the surface, which Kamina claimed he had visited as a young boy. Though Simon was an outcast, he would always feel more comfortable around Kamina. In one instance, Kamina and the other members were trapped in a small hole caused by an earthquake; everyone was scared, but Kamina's pep talks to Simon motivated the digger to drill a tunnel out of the barricade. After this incident, Kamina and Simon grew so close that they could have been called brothers.

Beastman War Arc
One day, during digging of a new tunnel, Simon discovers a small drill-shaped object that periodically glows, an item known as the Core Drill. On the same day, he unearths a large "face" in the ground, and shows it to Yoko and Kamina after Jeeha Village is attacked by a large Gunmen. The face is revealed to be a miniature Gunmen, and the Core Drill Simon dug up is the key to starting it. With the aid of this mech, which Kamina names the "Lagann", Simon destroys the large Gunmen attacking Jeeha and rises to the surface world.Most of the Team Gurren's early successes are directly because of Simon, particularly in the capture of the Gunzar (later, the Gurren) and entrapping the Dai-Gunzan in a desert sinkhole. However, for much of Part I, Simon is depicted as a sidekick to Kamina, his very presence overshadowed by his much more charismatic friend. Although Simon forms a fast friendship with the similarly aged Rossiu, and is admired by Rossiu's wards Gimmy and Darry, he often goes unnoticed or ignored by older members, particularly his crush, Yoko. This treatment of Simon ultimately proves fatal for Kamina when Yoko, oblivious to Simon's feelings for her, confesses her affection for Kamina with a kiss in front of a bewildered Simon (though both Yoko and Kamina are unaware that Simon is watching). This upsets Simon and disrupts his ability to control the Lagann, forcing Kamina to supervise him. While Kamina is caught off guard, Divine General Thymilph surprises and stabs Kamina, ultimately killing him. The guilt over Kamina's death reduces the morale for the Team Gurren, but it affects Simon to an extreme - mentally broken, bitter and depressed, he becomes hostile to friend and foe alike. Few members have any faith in Simon's capacity as a leader, and a power struggle begins between Simon and Kittan, ending in Simon soullessly yielding his rank. His psychotic tendencies have an adverse affect on the Gurren-Lagann, leading to surges of spiral energy that disrupt the mech's basic functioning, causing it to fall apart. The Lagann rejects Simon, deeming him unfit to pilot it properly in his unstable state. It is during this time Simon meets Nia, and the two immediately develop a strong friendship. Continually inspired and touched by her kindness and sincerity, Simon regains his composure to fight, renaming himself Simon the Driller. After this display, he is unanimously elected Team Gurren's new leader. He leads Team Dai-Gurren to Teppelin, where he defeats the spiral king.

Anti-Spiral War Arc
Upon defeating the Spiral King and putting an end to the war against the Beastmen, Simon becomes commander-in-chief of the city founded on Teppelin's remains, Kamina City, and effectively the leader of humanity and of Earth. During the seven years since their victory, the city flourishes by his and the Team Gurren's efforts, bringing a long sought period of peace. However, just after proposing marriage to Nia and receiving her positive reply, the one millionth human child is born, triggering the Anti-Spiral Human Annihilation System. Nia, who is turned into the Anti-Spirals' messenger, reveals to the population the whole truth behind their intentions and the reason why they plan to wipe out mankind, triggering a revolt from the people of Kamina City against the government, who destroys Kamina's statue and asks for Simon's head. In a maneuver to calm down the angry mob, Simon is betrayed by his second-in-command, Rossiu, who removes him from power and holds a mock trial where Simon is sentenced to death. Incarcerated in the Rinkane Jail until the day of his execution, he ends up meeting Viral, an old enemy of his, and after causing a commotion among the prisoners, both are sent to individual cells. During Simon's short time in jail, Nia appears before them and their ensuing conversation is interrupted by Yoko, who broke into the prison in order to rescue him. Before leaving, Simon also sets Viral free and the trio encounters the rest of the reformed Team Gurren who is finished with their preparations to retaliate against the Anti-Spirals. With Viral piloting the Gurren, Simon and his companions rush into space to protect the Arc-Gurren from a massive Anti-Spiral attack, forming the Arc-Gurren-Lagann in the process. After confronting Nia and making her briefly revert to her old self, Simon manages to convince her to let him stop the Human Annihilation System by taking control of the Cathedral Terra and keeping it from falling on Earth. Unfortunately, Nia is teleported back to the Anti-Spirals' homeworld, causing Simon to swear to rescue her. Leaving Rossiu at the command of Kamina City in his absence, Simon and the rest of Team Gurren take control of the Cathedral Terra, renamed the Chouginga Dai-Gurren, and launch themselves into deep space to recover Nia from the grasp of the Anti-Spirals. Due to a feint, Simon is forced to watch the deaths of almost all of Team Dai-Gurren's members when he tries to transform the Chouginga Dai-Gurren into the Chouginga Gurren-Lagann. After the death of Kittan, Simon transformers it but is stuck in a illusion by the Anti-Spiral King. Simon is freed by Kamina, and proceeds to free the others. The remaining members of the Dai-Gurren Dan claim Laganns free-floating in Anti-Spiral space, relics of previous campaigns, and their faith in Simon allows the creation of the Tengen Toppa Gurren Lagann. After an intense battle, Simon kills the Anti-Spiral King with Lagann Impact, accepting the responsibility to protect the universe for all humanity. After the final battle against the Anti-Spirals, Simon finally weds Nia, but that happiness is cut short when her body disappears due to her Anti-Spiral nature. Simon is not surprised, as he and Nia knew what would happen beforehand. When Gimmy suggest he use Spiral Power to revive the dead and bring Nia and their allies back to life, Simon refuses, claiming "the dead should stay dead." He then gives Lagann's Core Drill to Gimmy and leaves to wander the Earth with his companion Boota.

After Anti-Spiral War
Twenty years later, an elder Simon having only a staff tipped with a large drill and his loyal pet Boota by his side is seen in the outskirts of Kamina City. The epilogue reveals that the elder Simon is the opening narrator for all of the episodes in the series.

Outfit
Early in the show, Simon wore a simple blue vest like shirt. Once he joins Team Gurren, Simon gets the logo of Team Gurenn on his back. After the timeskip, Simon has a change of wardrobe, wearing grey, low-rise jeans, a black neck brace and plastic black haramaki, and donning a long, navy blue trenchcoat with gold studs, sporting the Team Dai-Gurren logo on the back. In both seasons, Simon wore digging goggles. He usually wore them on his head and only wore when digging. In season two, Simon's goggles turned into glasses similar to Kamina's, except that there is a large looking star in the middle. These glasses were destroyed during the final battle against the Anti-Spirals.

Piloting
Simon originally had no skills when using a Ganmen. Simon never really fought using Lagann as most of the time, he was in Gurenn-Lagann or taking control of a Ganmen. However, once Kamina dies, Simon becomes skilled enough to pilot Gurenn-Lagann by himself. Simon also was skilled enough to pilot the other forms of Gurenn-Lagann, Arc Gurren-Lagann, Chōginga Gurren-Lagann and Tengen Toppa Gurren-Lagann. He is also one of the few humans able to use spiral power. Some of the moves include the Giga Drill Breaker and one such as Drill missiles and drills that fly out and hit many foes.

Skills
Skilled Digger: Simon is a skilled digger and is one of the best diggers in his village. He saved himself and Kamina from Viral's powerful laser by digging a tunnel in almost an instant.

Skilled Ganmen Pilot: As a pilot, Simon is skilled enough to pilot Gurren-Lagann on his own. He fought Lordgenome with Lagann and destroyed the Razengan in single combat.

Fist Fighting: Simon is able to fight hand to hand, as shown when he fought Viral for a short time and punched Rossiu hard enough in the face to knock him backwards (though this may also be due to momentum).

Spiral Power - Simon has the ability to use spiral power since humans are spiral beings. Simon has a large amount of spiral energy and Lord Genome stated he has even more than him. He had no control of his spiral energy at first but after Kamina's death he gained more control and went to a level where he could pilot massive ganmen. His spiral power is infinite and is the most powerful being in the entire TTGL verse. He usually channels spiral energy into his core-drill but towards the end he learned to unleash it alone. He can fire massive beams of spiral energy from his core drill and can create drills for various purpouses the latter requiring a gunman.

Etymology
Simon's name comes from the Japanese word 'shimo', for 'under'. The pronunciation of his name in the Japanese-language version reflects this.

Trivia

 * Though the extent of his relationship with Nia is never fully explored, Gainax Studios has stated that "seven years is a long time" and that "During the seven year timeskip Simon and Nia did what had to be done." []
 * The Simon that appeared in the opening prolouge of Episode 1 was nicknamed "Garlock" by fans. Later on, his adult form was nicknamed "Starlock". Garlock refers to a character being "extremely manly". Starlock refers to SImon's goggles transforming into sunglasses