Treasure Chest is such a great D&D trope: will you find gold, or knowledge, or a relic of great power
This means Captain Marvel's cost would become just two mana
Various cards can add further power to the deck, such as the Goblin Anarchomancer, which makes green and red spells cheaper by one colourless mana, the Mage Slayer, which promises unblockable damage, or the Rhythm of the Wild enchantment, which protects your own creature spells from counterspells
Whether theyre pilfering their opponents decks or ruthlessly sacrificing their friends, rogues have all kinds of fun tricks up their sleeves
She's not similar
In decks capable of generating a lot of mana through rituals for example, this sounds very fun and powerful