With the announcement of Archmage Vargoth, I started wondering how this card would play in a OTK deck.

Most of the time in an OTK deck you are fishing for you combo-pieces, and this can at times cost you the game.

Making your combo more flexible should make it easier to get that OTK, one way or another.

With a saved coin and 1 discount from Emperor Thaurissan you can have a 6 mana Prophet Velen + 3 mana Archmage Vargoth + 2x 1 mana Mind Blast for 30 damage, and that is just one of the many ways this card can make your win condition more flexible.

In this scenario there is of course a chance that the coin gets copied, but sometimes needs must and all that, and a 66% succesrate isn't too bad for an ultimate gamble if you lose the next turn and have no other options.

Multiple discounts from Emperor Thaurissan (however unlikely), the opponent being at less hp (hey there Alexstrasza), Archmage Vargoth surviving a previous turn, ... It's just more ways to sqeeuze that win out of the game

These are a few of many ways though; you could just as easily use it for an extra Lightbomb or Spirit Lash for example to get you to your OTK turn.

The rest of the deck is build around a strong early game provided by the dragons to get you to the point of a OTK, with many ways to adapt to your opponent with cards like Firetree Witchdoctor, Netherspite Historian, Drakonid Operative and (if necessary) Shadow Visions for an extra AoE.

Control of the early game, or at the very least preventing a snowballing enemy, is the name of the game with the above cards until you can play Emperor Thaurissan and start mapping out the last turns of the game.

Dragon synergy activation should be no problem with the 8 dragons in the deck + the ability to add more due to Netherspite Historian.

I also find that once most players see the first dragons on the board, they usually don't expect an OTK anymore and stop playing around it and start playing more greedily like saving that Reno Jackson just one more turn, because what could go wrong right?

Brann Bronzebeard can be used as the situation warrants, as this deck is full of battlecry minions. Extra draw, a double Duskbreaker, double discoveries of spells or dragons, ...

Harrison Jones is a tech choice I've included at this time due to the many dangerous weapons in wild + the card draw for your combo-pieces, but he can easily be replaced by any other card with the same function should you find yourself sitting with a full hand in most games.