I have a Taunt Gyrados and I don't know how to use it. It is effing completely useless. Whats so good about taunt?
Case 1:
Gyarados uses Dragon Dance!
Player2 switches in Gallade
Hmm... I wonder what he's gonna do?
Gyarados uses Taunt!
Gallade uses T-Wave. Gallade can't use T-Wave after taunt!
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Gyarados uses Dragon Dance!
Player2 switches in Skarmory
Hmm... I wonder what he's gonna do?
Gyarados uses Taunt!
Skarmory uses Whirlwind. Skarmory can't use Whirlwind after taunt!
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Gyarados uses Dragon Dance!
Player2 switches in Starmie
Hmm.... I wonder what he's gonna do?
Player1 switches in Electavire / Jolteon
Starmie uses Thunder-bolt! Electavire / Jolteon gets a free boost
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Essentially, when Gyarados starts to dragon dance, there are only a few pokemon that can truely take him out before its too late. Those pokemon are taken out when Electivire comese in and screws their T-Bolt over. If its a status-type pokemon (Dusknoir, Skarm, Gallade, Togekiss...), you can almost be certain that they are going to try and status you. Right then, you taunt their status and prevent it, and continue to dragon dance.
Its not un-counterable (Gardevoir and Porygon2 are well known for taking both Gyarados out with T-Bolt, and Electivire out later by stealing his motar boost with Trace), nor is it without flaws. But thats the basic gist of this combo.