Slamming Atraxa on most boards wins you the game outright, and you just draw a bunch of cards to make up for it if your opponent can answer it
Formats Not Legalstandard Not Legalfuture Legalhistoric Legaltimeless Legalgladiator Not Legalpioneer Not Legalmodern Legallegacy Not Legalpauper Legalvintage Not Legalpenny Legalcommander Legaloathbreaker Not Legalstandardbrawl Legalbrawl Not Legalalchemy Not Legalpaupercommander Legalduel Not Legaloldschool Not Legalpremodern Not Legalpredh Not Legaltlr
Selvala's Stampede Okay, now were getting into nuttier material
PSA 10 copies consistently sell for $40,000+
Source: ebay (While this is very much not investment advice , at quick glance the seller does look legit according to their ebay profile, and specialized in traded graded cards, so this price point seems reasonable)
Then, negate the effects of all cards on the field, besides this card, and reduce the Attack and Defense of all face-up Monsters on the field to 0 besides this card