I decided to put this in Darkmoon because it fits flavor-wise, but also because a potential Spell Priest got some great support in Palm Reading and Auspicious Spirits, as well as Insight which can be used to tutor out any minions you might be using. Also, Galakrond is still in standard so it feels possible. And the card isn't bad even if the condition isn't met.

I feel like this is quite a powerful card, however if your deck has no minions the one pay off card should be worth it. By having no minions in your deck you essentially get a health swing of 12 because you don't take the damage you would, and your opponent takes it as well.

"Minions are easier to persuade to join you while you have a sharp object." The Shadowhunter is a glaive for Demon Hunters that can make up for the lack of minions by giving you one with a big discount (ala Skull of Gul'dan). And it synergizes with Outcast since it will be a lot easier to play it with the discount.

Shuffle 2 beast companions into your deck. If your deck has no minions, shuffle in 3.

Card text got longer than I expected.. Hope you like the card :)

This card would theoretically belong to a set where Shaman has a lot of token-generating spells.

Shaman is a class that is capable of running spell-heavy decks. With no minions in their deck, they can still summon Totems via the Hero Power and a few ways to summon minions through other card effects.

The card could also combo with Windshear Stormcaller as long as you draw it before you play this card.

"Plagiarism will not be tolerated at the Academy. Make sure you're the only source of the information." - Mindrender Illucia

'The soul of the party, being cooped up alone really saps the life out of him.'

The trees of the Witchwood hate intruders, especially when they bring their pets along to leave "presents" behind.

This card has two main uses:

1. As part of a spell thief-priest deck that uses the start of game effect and cards like Thoughtsteal to copy the opponent's strategy.

2. As a worse Archbishop Benedictus in a control Priest deck 

What balances the start of game effect is that it requires the player to spend 2 mana on it and only really takes effect on turn 3 (and forces the player to use subpar cards), as opposed to something like Baku the Mooneater that has a debatably less impactful condition, takes effect on turn 2, and costs 0 mana to play. Also, the discount is balanced when compared to a card like Incanter's Flow.

Thought that would be great for non-minion minion deck to not be spell themed but weapon themed. Not saying that Rogue looks quite well as no-minion class even without weapons, considering all its useful spells.

While this would certainly help building a No Minions Warrior deck, Light the Fuses! would probably have also found a home in The Boomsday Project's Control Warrior archetype. At 3 Mana it not only curves into Death's Bite which helps to trigger the Deathrattles if your opponent should choose to ignore them for some reason, but it can also be combo-ed with Dr. Boom, Mad Genius at 10 Mana so the Boom Bots gain Rush. Last but not least, Control Warrior was fairly successful for some time and mirror matches were frequently decided deep in fatigue - when the No Minions condition of this card would be met once more. 

He's in flame! Boomshakalaka!

As the mage no minions spells help to generate minions, I thought I'd give it a try for Paladin. The spell would be very underpowered without the bonus effect, however with the bonus effect it would be very useful.

"Look at all these Mana Crystals, unused and untouched!" "Great! Now, don't touch it."

A more fair Overgrowth normally but a much stronger Nourish when you're running no minions.