Returned deprecated StrengthBonusVsCityStates to work for the usual transitional period

core/src/com/unciv/logic/battle/BattleDamage.kt

@@ -109,6 +109,12 @@ object BattleDamage {
         if (strengthMalus != null) {
             modifiers.add("Adjacent enemy units", strengthMalus.params[0].toInt())
         }
+
+        // e.g., Mongolia - https://civilization.fandom.com/wiki/Mongolian_(Civ5)
+        if (enemy.getCivInfo().isCityState()
+            && civInfo.hasUnique(UniqueType.StrengthBonusVsCityStates)
+        )
+            modifiers["vs [City-States]"] = 30
     }
 
     private fun addResourceLackingMalus(combatant: MapUnitCombatant, modifiers: Counter<String>) {

core/src/com/unciv/models/ruleset/unique/UniqueType.kt

@@ -344,7 +344,7 @@ enum class UniqueType(
     Strength("[relativeAmount]% Strength", UniqueTarget.Unit, UniqueTarget.Global),
     StrengthNearCapital("[relativeAmount]% Strength decreasing with distance from the capital", UniqueTarget.Unit, UniqueTarget.Global),
     FlankAttackBonus("[relativeAmount]% to Flank Attack bonuses", UniqueTarget.Unit, UniqueTarget.Global),
-    @Deprecated("as of 4.9.0",ReplaceWith("[+30]% Strength <vs [City-States]>"), DeprecationLevel.ERROR)
+    @Deprecated("as of 4.10.3", ReplaceWith("[+30]% Strength <vs [City-States]>"))
     StrengthBonusVsCityStates("+30% Strength when fighting City-State units and cities", UniqueTarget.Global),
     StrengthForAdjacentEnemies("[relativeAmount]% Strength for enemy [combatantFilter] units in adjacent [tileFilter] tiles", UniqueTarget.Unit),
     StrengthWhenStacked("[relativeAmount]% Strength when stacked with [mapUnitFilter]", UniqueTarget.Unit),  // candidate for conditional!

docs/Modders/Unique-parameters.md

@@ -152,7 +152,9 @@ A filter determining a part of the population of a city. It can be any of the fo
 
 Can be any of:
 - [mapUnitFilter](#mapunitfilter), for unit combatants
-- "City", "All", or [civFilter](#civfilter), for city combatants
+- `City`, `All`, or [civFilter](#civfilter), for city combatants
+
+Since mapUnitFilter contains civFilter, that means civFilter can be applied to combatantFilter for both units and cities.
 
 ## regionType