diff --git a/PKHeX.Core/Legality/Checks.cs b/PKHeX.Core/Legality/Checks.cs
index d5a211cda..58b3672cb 100644
--- a/PKHeX.Core/Legality/Checks.cs
+++ b/PKHeX.Core/Legality/Checks.cs
@@ -1996,6 +1996,13 @@ namespace PKHeX.Core
                     AddLine(Severity.Invalid, V320, CheckIdentifier.Egg);
                 if (pkm.Format == 2 && (pkm.PKRS_Cured || pkm.PKRS_Infected))
                     AddLine(Severity.Invalid, V368, CheckIdentifier.Egg);
+                if (pkm is PK4 pk4)
+                {
+                    if (pk4.ShinyLeaf != 0)
+                        AddLine(Severity.Invalid, V414, CheckIdentifier.Egg);
+                    if (pk4.PokéathlonStat != 0)
+                        AddLine(Severity.Invalid, V415, CheckIdentifier.Egg);
+                }
 
                 var HatchCycles = (EncounterMatch as EncounterStatic)?.EggCycles;
                 if (HatchCycles == 0 || HatchCycles == null)
diff --git a/PKHeX.Core/Legality/LegalityCheckStrings.cs b/PKHeX.Core/Legality/LegalityCheckStrings.cs
index aee60e0ee..32e8f1b85 100644
--- a/PKHeX.Core/Legality/LegalityCheckStrings.cs
+++ b/PKHeX.Core/Legality/LegalityCheckStrings.cs
@@ -407,6 +407,8 @@ namespace PKHeX.Core
         public static string V410 {get; set;} = "Mystery Gift fixed PID mismatch.";
         public static string V411 {get; set;} = "Encounter Type PID mismatch.";
         public static string V412 {get; set;} = "Non-tradeback pre evolution move. Incompatible with Generation 1 exclusive moves.";
+        public static string V414 {get; set;} = "Eggs can not have Shiny Leaf/Crown."; // Invalid
+        public static string V415 {get; set;} = "Eggs can not have Pokéathlon stats."; // Invalid
         #endregion
 
     }
diff --git a/PKHeX.Core/PKM/PK4.cs b/PKHeX.Core/PKM/PK4.cs
index ad507f093..d56e40773 100644
--- a/PKHeX.Core/PKM/PK4.cs
+++ b/PKHeX.Core/PKM/PK4.cs
@@ -311,6 +311,7 @@ namespace PKHeX.Core
         public override int Met_Level { get => Data[0x84] & ~0x80; set => Data[0x84] = (byte)((Data[0x84] & 0x80) | value); }
         public override int OT_Gender { get => Data[0x84] >> 7; set => Data[0x84] = (byte)((Data[0x84] & ~0x80) | value << 7); }
         public override int EncounterType { get => Data[0x85]; set => Data[0x85] = (byte)value; }
+        public int PokéathlonStat { get => Data[0x87]; set => Data[0x87] = (byte)value; }
         // Unused 0x87
         #endregion
 
diff --git a/PKHeX.Core/Resources/text/en/LegalityCheckStrings_en.txt b/PKHeX.Core/Resources/text/en/LegalityCheckStrings_en.txt
index 81ea37865..ee1a48332 100644
--- a/PKHeX.Core/Resources/text/en/LegalityCheckStrings_en.txt
+++ b/PKHeX.Core/Resources/text/en/LegalityCheckStrings_en.txt
@@ -342,4 +342,7 @@ V408 = Female OT from Generation 1/2 is invalid.
 V409 = Mystery Gift shiny mismatch.
 V410 = Mystery Gift fixed PID mismatch.
 V411 = Encounter Type PID mismatch.
-V412 = Non-tradeback pre evolution move. Incompatible with Generation 1 exclusive moves.
\ No newline at end of file
+V412 = Non-tradeback pre evolution move. Incompatible with Generation 1 exclusive moves.
+V413 = Unreleased event.
+V414 = Eggs can not have Shiny Leaf/Crown.
+V415 = Eggs can not have Pokéathlon stats.
diff --git a/PKHeX.Core/Resources/text/ko/LegalityCheckStrings_ko.txt b/PKHeX.Core/Resources/text/ko/LegalityCheckStrings_ko.txt
index eff3e2564..a5b469c09 100644
--- a/PKHeX.Core/Resources/text/ko/LegalityCheckStrings_ko.txt
+++ b/PKHeX.Core/Resources/text/ko/LegalityCheckStrings_ko.txt
@@ -342,4 +342,7 @@ V408 = 1/2세대에서는 여성 어버이를 사용할 수 없습니다.
 V409 = 이상한소포의 색이 다른 포켓몬 여부가 일치하지 않습니다.
 V410 = 이상한소포의 고정된 PID가 일치하지 않습니다.
 V411 = 인카운터 유형 PID가 일치하지 않습니다.
-V412 = 이전 세대로 옮길 수 없는 진화 전 기술입니다. 1세대 전용 기술과 함께 존재할 수 없습니다.
\ No newline at end of file
+V412 = 이전 세대로 옮길 수 없는 진화 전 기술입니다. 1세대 전용 기술과 함께 존재할 수 없습니다.
+V413 = Unreleased event.
+V414 = Eggs can not have Shiny Leaf/Crown.
+V415 = Eggs can not have Pokéathlon stats.
diff --git a/PKHeX.Core/Resources/text/zh/LegalityCheckStrings_zh.txt b/PKHeX.Core/Resources/text/zh/LegalityCheckStrings_zh.txt
index 65ba5d962..edd5a9326 100644
--- a/PKHeX.Core/Resources/text/zh/LegalityCheckStrings_zh.txt
+++ b/PKHeX.Core/Resources/text/zh/LegalityCheckStrings_zh.txt
@@ -342,4 +342,7 @@ V408 = Female OT from Generation 1/2 is invalid.
 V409 = Mystery Gift shiny mismatch.
 V410 = Mystery Gift fixed PID mismatch.
 V411 = Encounter Type PID mismatch.
-V412 = Non-tradeback pre evolution move. Incompatible with generation 1 exclusive moves.
\ No newline at end of file
+V412 = Non-tradeback pre evolution move. Incompatible with generation 1 exclusive moves.
+V413 = Unreleased event.
+V414 = Eggs can not have Shiny Leaf/Crown.
+V415 = Eggs can not have Pokéathlon stats.
diff --git a/PKHeX.WinForms/Controls/PKM Editor/ShinyLeaf.cs b/PKHeX.WinForms/Controls/PKM Editor/ShinyLeaf.cs
index 2c1782c19..1eabc6e97 100644
--- a/PKHeX.WinForms/Controls/PKM Editor/ShinyLeaf.cs	
+++ b/PKHeX.WinForms/Controls/PKM Editor/ShinyLeaf.cs	
@@ -44,15 +44,17 @@ namespace PKHeX.WinForms.Controls
         {
             if (!(sender is CheckBox c))
                 return;
-            if (!c.Checked)
-                CHK_C.Checked = CHK_C.Enabled = false;
-            else if (Flags.Take(5).All(z => z.Checked) && CHK_C != c)
-                CHK_C.Enabled = true;
 
             if (CHK_C == c)
                 c.Image = c.Checked ? Resources.crown : greyCrown;
             else
+            {
+                if (!c.Checked)
+                    CHK_C.Checked = CHK_C.Enabled = false;
+                else if (Flags.Take(5).All(z => z.Checked))
+                    CHK_C.Enabled = true;
                 c.Image = c.Checked ? Resources.leaf : greyLeaf;
+            }
         }
     }
 }