This may be a little bit of an overreaction to Golgari Charm, and I know that I have been advocating this in the past
Your Basilisk Gate sees more Gates and consequently creates an enormous temporary buff for a target creature, for example
In Sultai colors, you can do some nasty things with this, from using Buried Alive/Entomb early on to setup a great later turn, to just replaying the Maha, Its Feathers Night and Toxrill, the Corrosive that your opponents worked so so hard to get rid of
Thing go well, and you only need one more win to make the Top 8
Merfolk is a good one, Wizards can go mono blue (Patron Wizard), loads of combo decks and artifact ramp decks are also fine to be mono blue for
Youre going to be paying around 3 mana and having to cycle two whole cards just to kill most early threats