War of the Spark

Elite Guardmage | Creature | Human Wizard | Flying When Elite Guardmage enters the battlefield, you gain 3 life and draw a card. | PINDURSKI

Gleaming Overseer | Creature | Zombie Wizard | When Gleaming Overseer enters the battlefield, amass 1. (Put a +1/+1 counter on an Army you control. If you don't control one, create a 0/0 black Zombie Army creature token first.) Zombie tokens you control have hexproof and menace. | Volkan Baǵa

Soul Diviner | Creature | Zombie Wizard | {T}, Remove a counter from an artifact, creature, land, or planeswalker you control: Draw a card. | Randy Vargas

Bioessence Hydra | Creature | Hydra Mutant | Trample Bioessence Hydra enters the battlefield with a +1/+1 counter on it for each loyalty counter on planeswalkers you control. Whenever one or more loyalty counters are put on planeswalkers you control, put that many +1/+1 counters on Bioessence Hydra. | Mathias Kollros

Merfolk Skydiver | Creature | Merfolk Mutant | Flying When Merfolk Skydiver enters the battlefield, put a +1/+1 counter on target creature you control. {3}{G}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.) | Sara Winters

Roalesk, Apex Hybrid | Legendary Creature | Human Mutant | Flying, trample When Roalesk, Apex Hybrid enters the battlefield, put two +1/+1 counters on another target creature you control. When Roalesk dies, proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.) | Svetlin Velinov

Niv-Mizzet Reborn | Legendary Creature | Dragon Avatar | Flying When Niv-Mizzet Reborn enters the battlefield, reveal the top ten cards of your library. For each color pair, choose a card that's exactly those colors from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order. | Raymond Swanland