Guilds of Ravnica

Erratic Cyclops | Creature | Cyclops Shaman | Trample Whenever you cast an instant or sorcery spell, Erratic Cyclops gets +X/+0 until end of turn, where X is that spell's mana value. | Milivoj Ćeran

Beast Whisperer | Creature | Elf Druid | Whenever you cast a creature spell, draw a card. | Matt Stewart

Etrata, the Silencer | Legendary Creature | Vampire Assassin | Etrata, the Silencer can't be blocked. Whenever Etrata deals combat damage to a player, exile target creature that player controls and put a hit counter on that card. That player loses the game if they own three or more exiled cards with hit counters on them. Etrata's owner shuffles Etrata into their library. | Bastien L. Deharme