Implements Hail

PkmnLib.Dynamic/Models/DamageSource.cs

@@ -25,4 +25,9 @@ public enum DamageSource
     /// This happens when the form of a Pokemon changes, and it has less max HP than it had before.
     /// </summary>
     FormChange = 3,
+    
+    /// <summary>
+    /// The damage is done because of the weather.
+    /// </summary>
+    Weather = 4,
 }