T.G. aka Tech Genus

"T.G.", short for "Tech Genus" (TG(テックジーナス) Tekkujīnasu) is an archetype used by Antinomy in Yu-Gi-Oh! 5D's. They are all bionic in appearance to reference the identity of their user. They made their debut in Extreme Victory. In the Japanese anime, each of them has a code in their name which references their Type, followed by a number. This includes their status as they have X's at the end of their names to indicate their evolution of Synchro Monsters:

Synchro - X
Accel Synchro - XX
Delta Accel Synchro - XXX.

They are high tech monsters from the future and they share a variation of this effect in anime:

This card can also be treated as a Machine-Type monster. When a Spell or Trap Card you control targets this card, you can halve this card's original ATK and DEF. When this card is destroyed, you can add 1 "T.G." monster card from your Deck to your hand. You cannot Summon it this turn.

In Yu-Gi-Oh! 5D's Tag Force 5, it is possible to use the card obtained during the same turn, and the ATK and DEF reduction is not present among their effects.

The real life version of the "T.G." cards consist of monsters who can "replace" themselves with different monsters when they're destroyed. Most of the non-Synchro Monsters search for other "T.G." monsters besides ones that share their name (for example, a "T.G. Warwolf" can search for any "T.G." monster besides "T.G. Warwolf"), while all of the Synchro Monsters (except "T.G. Recipro Dragonfly") draw cards or Summon monsters.

Despite their bionic appearance and names, the only existing Machine-Type "T.G." monsters are Accel Synchro Monsters. All "T.G." supporting Spell and Trap Cards have an initialism in their names.

Playing Style

The goal of the archetype is to Accel Synchro Summon "T.G." monsters to control the field. "T.G. Blade Blaster" can negate Spells and Traps while "T.G. Halberd Cannon" can negate Summons. Due to the ease of low-Level Synchro Summons, Summoning the two aforementioned monsters is a matter of summoning and protecting the Synchro Material Monsters. A good rival of "T.G. Halberd Cannon" is "Shooting Quasar Dragon" due to the high attack stats and powerful effects. Although "Shooting Quasar Dragon" is prefered due to the multiple attacking ability.

"T.G. Striker", "T.G. Warwolf", and "T.G. Catapult Dragon" are the best cards to swarm with; the first two have easy Summoning requirements while "Catapult Dragon" can Summon more monsters and give "Warwolf" an opportunity to be Summoned by its effect. At the very least, in case you cannot Synchro Summon, you can build a defense and let your opponent destroy them, giving you plenty of cards to add to your hand at the End Phase.

Some good support cards are "Junk Synchron", "Kinka-byo", and "Mischief of the Yokai".

When Normal Summoned, "Junk Synchron's" effect can Special Summon "Catapult Dragon" from the Graveyard so you can Synchro Summon any of the Level 5 "T.G." Synchro Monsters. Be sure that at least one of those monsters is "T.G. Hyper Librarian", to gain extra draw power.
Because there are no Level 1 "T.G." non-Tuner monsters for "Recipro Dragonfly", you can use "Kinka-byo's" effect to summon "T.G. Cyber Magician" from the Graveyard. This combo can also Synchro Summon "Formula Synchron" so you can draw 1 card.
"Mischief of the Yokai" can be used offensively or defensively. Since the non-Synchro Monsters are for Synchro Summoning Level 5 Synchro Monsters, using "Mischief" reduces the Levels of "Striker", "Warwolf", and "Catapult Dragon" to 1 without any drawback to "T.G. Blade Blaster", since it will most likely be on the field first.

Also, since the "T.G." cards share the ability to search once they are destroyed, support cards such as "Kuraz the Light Monarch" and "Needle Ceiling" can be used with little or no drawbacks. While "Kuraz's" effect might seem too good to pass up on your own cards, remember that you can use it selectively: for example, you can choose to destroy your opponent's "Legendary Six Samurai - Shi En" and not target any of their other monsters.

Because of the extensive use of Level 5 Synchro Monsters, a T.G. Deck can use "Ally of Justice Catastor", "T.G. Hyper Librarian", and in some cases Naturia Beast.

Summoning the ace of this archetype ("T.G. Blade Blaster") it's relatively fast and can be done in a single turn if you control no monsters and your opponent does while you have in your hand to Special Summon "T.G. Striker" and "T.G. Warwolf", then Normal Summon "T.G. Cyber Magician" with "T.G. Rush Rhino" in your hand or Normal Summon "T.G. Catapult Dragon" and Special Summon "T.G. Jet Falcon" from your hand. In the event that you don't have all of them in your hand, then you can let your opponent destroy a few of your T.G. monsters that can search the Deck for other T.G. monsters during the end phase to build up the resources to "Accel Synchro Summon" "T.G. Blade Blaster" quickly.

On the other hand, the summoning of the strongest T.G. monster, "T.G. Halberd Cannon", it's very easy when you have "T.G. Blade Blaster" on your field and you have at least "T.G. Cyber Magician" in your hand and "Level Eater" in your graveyard. Normal Summon "T.G. Cyber Magician", then activate "Level Eater"'s effect in your graveyard by reducing "T.G. Blade Blaster"'s Level by 1 to revive "Level Eater". Tune "T.G. Cyber Magician" with "Level Eater" to "Synchro Summon" "T.G. Recipro Dragonfly", and activate it's effect to send your "T.G. Blade Blaster" to the graveyard and Special Summon the synchro material monsters used for it provided you have them in the graveyard, and finally tune "T.G. Recipro Dragonfly" with "T.G. Wonder Magician" and the other Level 5 "Synchro Monster" to "Delta Accel Synchro Summon" "T.G. Halberd Cannon". "Level Eater" it's also useful for many aspects in this Deck.

"Plaguespreader Zombie" can also be used in this Deck to accelerate the rate of "Synchro Summon". Cards like "Gravity Collapse" (negates a summon and destroys the monster making the oponent unable to summon more monster for the rest of the turn by tributing one of your "Synchro Monster"), "Synchro Material" ("steals" an oponent's monster that you can use to Synchro Summon), "Safe Zone" (protects 1 of your monsters from any kind of destruction and targeting effects by giving up direct attacks with the monster you are protecting with it) and specially, "Inferno Reckless Summon" (summons 1 or 2 more copies of a T.G. monster from your graveyard, hand or Deck when you special summoned one T.G. monster which makes the combo even better if you don't use the spare monsters special summoned by this effect and let them be destroyed to search the Deck at the end phase), are a staple in this Deck to keep the opponent under constant pressure and control even if they use a fast and powerful Archetype like the "Six Samurai" or to some extent, "Blackwings".
T.G. Deck (Junk Doppel Tengu Plants engine)
Recommended cards
Monsters

Reborn Tengu
T.G. Rush Rhino
T.G. Striker
T.G. Warwolf
Lonefire Blossom
T.G. Cyber Magician
Dandylion
Junk Synchron
Thunder King Rai-Oh
Doppelwarrior
T.G. Jet Falcon
Card Trooper
Spore

Spells

Pot of Avarice
Mind Control
Forbidden Lance
Creature Swap

Traps

Seven Tools of the Bandit
Divine Wrath
Horn of the Phantom Beast
Safe Zone
TG1-EM1
Solemn Warning

Extra Deck

Ally of Justice Catastor
Armory Arm
Colossal Fighter
Formula Synchron
T.G. Power Gladiator
T.G. Wonder Magician
T.G. Blade Blaster
T.G. Hyper Librarian
Black Rose Dragon
Mist Wurm
Stardust Dragon
Naturia Barkion
Naturia Beast
Gaia Knight, the Force of Earth
Red Dragon Archfiend
Red Nova Dragon
T.G. Halberd Cannon
Shooting Quasar Dragon
Shooting Star Dragon

T.G. Stun
Recommended cards
Monsters

Reborn Tengu
Photon Sabre Tiger
Hazy Flame Cerbereus
Photon Thrasher
T.G. Rush Rhino
T.G. Striker
T.G. Warwolf
Thunder King Rai-Oh
Beast King Barbaros
Plaguespreader Zombie
Tardy Orc
Black Luster Soldier - Envoy of the Beginning

Spells

Pot of Avarice
Pot of Duality
Creature Swap
Reinforcement of the Army (If Running 3 or More Warrior)
The Seal of Orichalcos
The Big Cattle Drive

Traps

Skill Drain
Starlight Road
Dark Bribe
TG1-EM1
Compulsory Evacuation Device
Torrential Tribute
Horn of the Phantom Beast

Extra Deck

Ally of Justice Catastor
Armory Arm
Colossal Fighter
Scrap Dragon
Formula Synchron
T.G. Power Gladiator
T.G. Wonder Magician
T.G. Hyper Librarian
Naturia Barkion
Mist Wurm
Ally of Justice Decisive Armor
Stardust Dragon
Black Rose Dragon
Leviair The Sea Dragon

Junk T.G.

While it lacks the searching power of other T.G. Decks, this variant focuses on combos with "Junk Synchron", "T.G. Catapult Dragon", and "T.G. Jet Falcon".
Monsters

Junk Synchron
T.G. Catapult Dragon
T.G. Jet Falcon
Doppelwarrior
Synchron Explorer
Ryko, Lightsworn Hunter
Dark Armed Dragon
T.G. Rush Rhino
T.G. Warwolf

Extra Deck

T.G. Blade Blaster
T.G. Hyper Librarian
T.G. Wonder Magician
T.G. Power Gladiator
Frozen Fitzgerald
Junk Berserker
Ally of Justice Decisive Armor
Stardust Dragon

Spells

Tuning
Dark Eruption
Foolish Burial

Traps

TG-SX1
Safe Zone
Ultimate Offering

Weaknesses

Since this archetype is one of the most Synchro-focused archetypes, rivaling Yusei-themed and Inca Decks, all anti-Synchro support ("Discord", "Synchro Control", "Greed Grado", "Meklords", "Shiny Black "C"", etc.) can kill the Deck, in addition to all the typical Anti-Meta strategies that most Decks fall prey to. None of the non-Synchro Monsters provide any offensive capabilities, barring "Rush Rhino" with "TGX300" on the field. "Thunder King Rai-Oh" can also stop their searching. Use "TG1-EM1" to take control of your opponent's monster when you don't have strong attack power. Also, nearly all monsters have effects that ease the Synchro Summons while wrecking havoc on the player's hand. Therefore, field clearing becomes even more important so protect your monsters with "Starlight Road" or "My Body as a Shield".