Ill put some of the highlights in order, then gold, just for people to know what they can expect out of these: Kenrith, the Returned King Akroma's Will Urza, Lord High Artificer Counterspell Cryptic Command Rhystic Study Yawgmoth, Thran Physician Bolas's Citadel K'rrik, Son of Yawgmoth Ragavan, Nimble Pilferer Ancient Copper Dragon Primeval Titan Atraxa, Grand Unifier Tymna the Weaver Isshin, Two Heavens as One Thrasios, Triton Hero #45
The third volume in the series, following the Official Collectors Guide: Sets 14 and the Official Collectors Guide: Sets 58
To that end, Set 4 featured a separate side-game you could purchase, 'Illumineer's Quest: Deep Trouble,' which put a neat cooperative spin on the standard Lorcana gameplay as you and a chum worked together to take down an automated Ursula deck
Add on Karumonix's ability to refill your hand with Rats , and you've got a stellar Rat commander