Stronghold
Stronghold is the thirteenth Magic expansion and was released in 1998 as the second set in the Tempest Block.
Mechanics & Abilities
The block mechanics Buyback and Shadow are expanded upon in this set.
The ability associated with the en-Kor are introduced in this set. The abilities associated with Slivers, Licids, Flowstone and especially Spikes are expanded upon in this set.
Cycles
Legendary Land mega-mega cycle: Volrath's Stronghold is the second card in this mega-mega cycle, which also includes Teferi's Isle, Yavimaya Hollow, Kor Haven, and Keldon Necropolis.
Sliver cycle: Crystalline Sliver, Hibernation Sliver, Acidic Sliver, Spined Sliver, and Victual Sliver.
Licid cycle: Calming Licid, Gliding Licid, Corrupting Licid, Convulsing Licid, and Tempting Licid.
Wall cycle: Wall of Essence, Wall of Tears, Wall of Souls, Wall of Razors, and Wall of Blossoms.
Points of Interest
Stronghold was the first set to feature a five-coloured card, Sliver Queen. It's casting cost of 1 of each colored mana is often referred to as "WUBRG" [pronounced woo-berg]