6 Koga A Substitute For Switch By all means, Koga should have the same problems as Blaine, considering it is limited to being used on Pokemon such as Muk or Weezing
The Commanders of the Knights of Hanoi arrived, and then Spectre and Soulburner entered Windy's palace

Blackmail Target player reveals three cards from their hand and you choose one of them for that player to discard Duress Target opponent reveals their hand and you choose a noncreature, nonland card for that player to discard Encroach Target player reveals their hand and you choose a nonbasic land card for that player to discard (can hit non-basic lands!!) Grief A 3/2 creature with Evoke (Evoke cost is exile a black card from your hand) When it enters the battlefield, target opponent reveals their hand and you choose a nonland card for that player to discard Inquisition of Kozilek Target player reveals their hand and you choose a nonland card from it with mana value 3 or less for that player to discard Mires Toll Target player reveals a number of cards from their hand equal to the number of Swamps you control and you choose one of them for that player to discard Thoughtseize Target player reveals their hand and you choose a nonland card for that player to discard you lose 2 life Unmask Exile a black card from your hand rather than pay this spells mana cost Target player reveals their hand and you choose a nonland card for that player to discard There are tons and tons of Black discard effects in MTG

This could have been fine if Darkfire Dragon had decent stats, but even the majority of other Main Deck monsters from this booster can easily attack over a monster that requires using three cards to summon
Only the most classic cards
You'll be disrupting the plans of your opponents by forcing attacks they don't want to make and if all goes well, your opponents will take each other out and leave you with one opponent staring own a flight of dragons