Sun & Moon and Sword & Shield Chase cards, alt arts, Rainbow Rares, Gold Rares and popular GX/V/VMAX cards
Personally, I see commander as a world of boardwipes, where equipment lay on the battlefield after wrath after wrath after wrath, so the idea that this sets up your first creature to equip to cheaply making her more of a hopeful Sigardas Aid than anything else
Its not always easy to predict 150+ cards and their viability before the set release, so take this list as a guideline to help you choose which cards to pick up
Something that grants your opponent and yourself a benefit is really difficult to justify in a competitive game
(Quick Effect): You can Tribute this card, then target 3 of your Dragon Monsters with different names in your GY
To keep your cards coming back, keep Winter, Cynical Opportunist as your commander