Promo cards are interesting because they are often seen as cheap or common upon release, but as the years go on, and fewer copies exist in circulation, the card will continue to increase in price and command a ton of value
(Damage and effects that say destroy dont destroy them.) Illustrated by Svetlin Velinov Standard Legal Alchemy Legal Pioneer Legal Historic Legal Modern Legal Brawl Legal Legacy Legal Comp
This version of Rakdos is a six mana 6/6 with flying and trample, which makes them useful even without flipping any coins
Though none of these cards are typically double-sided, the Secret Lair versions have art on both sides, with puzzles - a sudoku, wordsearch, and matching game - alongside the full card text on their back faces
If your commander has no creature types, it can't share a creature type with any spell that you cast