The search results indicate that "5.2.4" is most commonly associated with Marvel Contest of Champions (MCOC) rather than Clash of Clans . In MCOC,
Keywords used: Clash of Clans 5.2.4, 5.2.4 update, Clash of Clans patch notes, TH9 meta 2015, old Clash of Clans, shield system rework, Town Hall sniping removal.
The Poison Spell simplified this interaction. Dropping a Poison spell on enemy troops slowed their movement and dealt damage over time. This changed the defensive meta significantly; it made low-hitpoint troops (like Archers and Wizards) less viable as defensive CC donations, pushing players toward high-hitpoint tanks like Dragons or Golems to survive the poison.
Why this mattered: This patch single-handedly invented the "LavaLoon" (Lava Hound + Balloon) strategy. Within weeks, the leaderboards shifted from ground-heavy attacks to aerial domination.