Merfolk Trickster Merfolk Trickster might be one of the most annoying creatures to Aether Vial into play, at least for your opponents
Study Lastly, the blue/black Investigate land card from Secret Passage Ravnica: Clue Edition
The fact that you can cast Tiamat with this in play and put five dragons on the table is very interesting and splashy, but in competitive MTG, this spells win more. Either way, this card can create loops when you cast a dragon again and again for free, but youre either cheating Dracogenesis into play or dumping 8 mana into it Omniscience is already a thing, by the way
It's very likely, in the right deck, to be mana positive and tap for more than the mana it took to drop it
Sebastian Rosenauer The first one-mana spell on our list and an essential piece in the black toolbox