Guilds of Ravnica

Venerated Loxodon | Creature | Elephant Cleric | Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.) When Venerated Loxodon enters the battlefield, put a +1/+1 counter on each creature that convoked it. | Zack Stella

Omnispell Adept | Creature | Human Wizard | {2}{U}, {T}: You may cast an instant or sorcery spell from your hand without paying its mana cost. | Jason Rainville

Gruesome Menagerie | Sorcery | | Choose a creature card with mana value 1 in your graveyard, then do the same for creature cards with mana value 2 and 3. Return those cards to the battlefield. | Yeong-Hao Han

Vivid Revival | Sorcery | | Return up to three target multicolored cards from your graveyard to your hand. Exile Vivid Revival. | Yeong-Hao Han