The "Watt" archetype consists of low ATK LIGHT monsters with effects mostly revolving around attacking and the Battle Phase. "Watts" have effects that activate after attacking directly, being destroyed by your opponent's cards, or just simply battling. These secondary effects can restrict the opponent's ability to activate effects, although many other types of effects also exist. The two main strategies of the Deck are: an aggressive Deck relying on the Level 4 "Watts" to inflict damage through direct attacks, or using a lockdown by assembling two face-up copies of "Watthopper", which prevents the opponent from targeting all "Watt" monsters for attacks and card effects.
Archetypes and monsters like the "Ally of Justice" monsters benefit from the many LIGHT monsters "Watts" have.
King Tiger Wanghu can shut down a "Watt" deck with its effect to destroy monsters Summoned with 1400 ATK or less. Other than the Synchro "Watt" monsters, "Watt" monsters have less than 1400 ATK, so they will be destroyed by his effect.
Since most "Watts" have effects that revolve around the Battle Phase, cards that prevent attacks, like the Mirror Trap series and Battle Fader, can easily stop the deck.