The uncommon counterspell (two options below) is also very good for limited
Grim Monolith ($472) Grim Monolith is at the heart of many infinite mana combos

7 Island 7 Mountain 8 Forest Aberrant Abundance Acolyte Hybrid Aetherize Arcane Signet Ash Barrens Biophagus Bred for the Hunt Broodlord Cave of Temptation Cinder Glade Clamavus Command Tower Cultivate Deathleaper, Terror Weapon Death's Presence Evolving Wilds Exocrine Exotic Orchard Explore Farseek Frontier Bivouac Game Trail Genestealer Locus Genestealer Patriarch Ghyrson Starn, Kelermorph Hardened Scales Harrow Haruspex Herald's Horn Hull Breach Icon of Ancestry Inspiring Call Magus Lucea Kane Malanthrope New Horizons Opal Palace Overgrowth Path of Ancestry Purestrain Genestealer Rampant Growth Ravener Rugged Highlands Sol Ring Sporocyst Starstorm Temple of Abandon Temple of Epiphany Temple of Mystery Termagant Swarm Terramorphic Expanse The First Tyrannic War The Red Terror Thornwood Falls Trygon Prime Tyranid Harridan Tyranid Invasion Tyranid Prime Unclaimed Territory Winged Hive Tyrant NEXT: Magic The Gathering: Everything You Need To Know About The Commander Format

Chimil, the Inner Sun is an artifact with the triggered ability "at the beginning of your end step, Discover 5"
The third digital-only mechanic is called Conjure , which creates a card for you to use out of nowhere not a token or a copy, but an actual card that can sit in your hand until you are ready to use it
This means when Archpriest of Shadows enters the battlefield, you can put a +1/+1 counter on a creature, and it gains the rest of Archpriest's abilities