Xantid Swarm stops the defending player from casting spells on the turn it attacks, opening a window to resolve key enchantments without fear of Counterspell or Mana Leak. Tsabo's Web draws a card when it enters and keeps Mishra's Factory, Faerie Conclave, and Dust Bowl from untapping once they are tapped, since each has an activated ability that isn't a mana ability, which slows down their manlands and land destruction. We keep both Swords to Plowshares copies and the full Solitary Confinement suite. Wrath of God only destroys creatures, and Powder Keg only destroys artifacts and creatures with the matching mana value, so neither one touches our enchantment-based lock. Abeyance and the extra Replenish are lower-impact here, so they make room for the more proactive additions.