"Brohunder", "Pahunder", "Mahunder" and "Sishunder"
"hunder", known as "Thunder" (サンダー, Sandā) in Japan, is an archetype used by Thunder Spark in the Yu-Gi-Oh! ZEXAL manga. It is composed of Level 4 Thunder monsters whose names are puns that indicate members of a family. The archetype is solely supported by "OToNaRiThunder".
The names in Japan were originally based on a pun involving their phonetic spelling. This pun used the first three letters of their names in relation to the Japanese honorifics: Oto-san, Oka-san, One-san, and Onii-san. Their English equivalents are Father, Mother, Sister and Brother respectively.
This archetype's focus is to Normal Summon multiple Level 4 LIGHT Thunder type monsters in one turn to Xyz Summon Rank 4 monsters such as "Number 91: Thunder Spark Dragon". Then, you can continue using their effects by replenishing Xyz Materials using "Spirit Converter", which allows you to attach one Level 4 LIGHT monster as an Xyz Material to an Xyz Monster on the field. This means that you can reuse monster effects like the attack negation of "Number 39: Utopia", or the second effect of "Number 91: Thunder Spark Dragon".
There are two common playing styles to this archetype -- Control and Swarm.
For the Swarm strategy, because of the abilities of Mahunder and Pahunder, you can perform multiple Normal Summons to land large amounts of damage on your opponent provided all of your monsters attack directly. This can be improved by Solidarity; however, be aware there are no Thunder-Type Xyz monsters that can be supported by this archetype at this time, and thus if you Xyz Summon, you may cause Solidarity's effect to become null. You can use Dimensional Fissure to help evade this, as the Xyz Materials will go to the Graveyard, but the Xyz Monster(s) will be Banished. You can also use Scrap Dragon (if your deck runs Vylon Prism) and destroy the now-useless Spell card if necessary.
For the Control strategy, you'd want to focus on dropping 1 Xyz at a time (such as Starliege Paladynamo or Constellar Omega) for your opponent to be pressured by, while maintaining a powerful hand advantage by using Thunder Seahorse, Sishunder and Recycling Batteries. Support your Xyz monster with cards such as Kaiser Colosseum, Effect Veiler, Honest, and other various Spells, Traps, and Effect Monsters. Then during the next turn, play another Xyz Monster to either regain, maintain, or further improve your advantage. Using Tragoedia in this strategy is a great defense mechanism that can turn into a powerful offense, as you can generally keep a large hand consisting of 4 or more cards consistently.
Because this archetype has such flexibility, you can take portions of both strategies and implement them into a single deck. You can use control cards in a swarm strategy to keep your opponent from countering you; you can Summon multiple monsters at once in a control strategy to inflict the final blow to your opponent after you've countered all of their other options.
In addition, because of the numerous Level 4 LIGHT Thunder-Types that currently exist, you can take this deck and create multiple hybrids -- Batteryman Hunders (Batteryman AAA and Batteryman 9-Volt), Watt Hunders (Wattcobra, Wattgiraffe, and Wattpheasant), or even Elemental HERO Hunders (Elemental HERO Voltic).
An easy way to incorporate Synchro Summoning into this archetype is to run the Tuner monster Vylon Prism, due to its ability of being added to your hand by Thunder Sea Horse and is summonable by Pahunder and Mahunder.