This whole concept brings to mind the popular Game Cube Game Gale of Darkness which saw you purifying Pokemon, and was also an in game mechanic introduced into Pokemon GO
There are some very relevant cards which dodge IoK like Yawgmoth, Thran Physician, Goblin Charbelcher, Omnath, Locus of Creation, Primeval Titan or any of the new Elementals, but just looking at the list of most played cards in Modern shows how many other cards Inquisition of Kozilek hits
6th Edition is in my "Magic gap" of 1997-2001 where I wasn't actively playing, so I'm not sure if it was designed to be drafted, and the interwebs were less helpful than usual, but I believe so.) Note that there still would be a small amount of Pauper cards without the proper rarity color coding from Mirage block and Tempest, but that would be it
Its just shorthand for an additional mana cost you can also pay by tapping your artifacts or creatures
However, sets like Surging Sparks stand out as special due to the contents of the product, which include gorgeous Special Illustration Rares (SIRs) of some of the most popular Pokemon ever
