diff --git a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8Nest.cs b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8Nest.cs
index ddebd3f41..7eb679e62 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8Nest.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8Nest.cs
@@ -43,7 +43,7 @@ public override bool IsMatchDeferred(PKM pkm)
         {
             if (base.IsMatchDeferred(pkm))
                 return true;
-            if (pkm is IGigantamax g && g.CanGigantamax != CanGigantamax && !Legal.CanEatMaxSoup.Contains(Species))
+            if (pkm is IGigantamax g && g.CanGigantamax != CanGigantamax && !g.CanToggleGigantamax(pkm.Species, Species))
                 return true;
             if (Species == (int)Core.Species.Alcremie && pkm is IFormArgument a && a.FormArgument != 0)
                 return true;
diff --git a/PKHeX.Core/Legality/Tables/Tables8.cs b/PKHeX.Core/Legality/Tables/Tables8.cs
index ae9d9539a..cdb60fa7e 100644
--- a/PKHeX.Core/Legality/Tables/Tables8.cs
+++ b/PKHeX.Core/Legality/Tables/Tables8.cs
@@ -246,41 +246,6 @@ public static partial class Legal
             798, 802,
         };
 
-        public static readonly HashSet<int> CanEatMaxSoup = new HashSet<int>
-        {
-            (int)Species.Venusaur,
-            (int)Species.Charizard,
-            (int)Species.Blastoise,
-            (int)Species.Rillaboom,
-            (int)Species.Cinderace,
-            (int)Species.Inteleon,
-            (int)Species.Butterfree,
-            (int)Species.Pikachu,
-            (int)Species.Meowth,
-            (int)Species.Machamp,
-            (int)Species.Gengar,
-            (int)Species.Lapras,
-            (int)Species.Eevee,
-            (int)Species.Snorlax,
-            (int)Species.Garbodor,
-            (int)Species.Drednaw,
-            (int)Species.Corviknight,
-            (int)Species.Toxtricity,
-            (int)Species.Alcremie,
-            (int)Species.Duraludon,
-            (int)Species.Orbeetle,
-            (int)Species.Coalossal,
-            (int)Species.Sandaconda,
-            (int)Species.Grimmsnarl,
-            (int)Species.Flapple,
-            (int)Species.Appletun,
-            (int)Species.Hatterene,
-            (int)Species.Copperajah,
-            (int)Species.Kingler,
-            (int)Species.Centiskorch,
-            (int)Species.Urshifu
-        };
-
         internal static readonly HashSet<int> GalarOriginForms = new HashSet<int>
         {
             (int)Species.Meowth,
diff --git a/PKHeX.Core/MysteryGifts/WC8.cs b/PKHeX.Core/MysteryGifts/WC8.cs
index b2d6245d6..82f988964 100644
--- a/PKHeX.Core/MysteryGifts/WC8.cs
+++ b/PKHeX.Core/MysteryGifts/WC8.cs
@@ -562,7 +562,7 @@ protected override bool IsMatchExact(PKM pkm)
             if (Nature != -1 && pkm.Nature != Nature) return false;
             if (Gender != 3 && Gender != pkm.Gender) return false;
 
-            if (pkm is IGigantamax g && g.CanGigantamax != CanGigantamax && !Legal.CanEatMaxSoup.Contains(Species))
+            if (pkm is IGigantamax g && g.CanGigantamax != CanGigantamax && !g.CanToggleGigantamax(pkm.Species, Species))
                 return false;
 
             if (!(pkm is IDynamaxLevel dl && dl.DynamaxLevel >= DynamaxLevel))
diff --git a/PKHeX.Core/PKM/Shared/IGigantamax.cs b/PKHeX.Core/PKM/Shared/IGigantamax.cs
index 376a1542a..551527242 100644
--- a/PKHeX.Core/PKM/Shared/IGigantamax.cs
+++ b/PKHeX.Core/PKM/Shared/IGigantamax.cs
@@ -1,4 +1,6 @@
-namespace PKHeX.Core
+using System.Collections.Generic;
+
+namespace PKHeX.Core
 {
     /// <summary>
     /// Interface that exposes an indication if the Pokémon can Gigantamax.
@@ -13,10 +15,64 @@ public interface IGigantamax
 
     public static class GigantamaxExtensions
     {
+        /// <summary>
+        /// Checks if either of the input Species can consume the Gigantamax soup, toggling the <see cref="IGigantamax.CanGigantamax"/> flag.
+        /// </summary>
+        /// <param name="_">Unnecessary, just needed for extension method usage.</param>
+        /// <param name="currentSpecies">The current species</param>
+        /// <param name="originSpecies">The original species (what species it was encountered as)</param>
+        /// <returns>True if either species can toggle Gigantamax potential</returns>
         public static bool CanToggleGigantamax(this IGigantamax _, int currentSpecies, int originSpecies)
         {
-            var soup = Legal.CanEatMaxSoup;
-            return soup.Contains(currentSpecies) || soup.Contains(originSpecies);
+            var soup = CanEatMaxSoup;
+            return soup.Contains(currentSpecies) || (currentSpecies != originSpecies && soup.Contains(originSpecies));
         }
+
+        /// <summary>
+        /// Don't use this method. Use the other overload with multi-species input.
+        /// </summary>
+        /// <param name="_">Unnecessary, just needed for extension method usage.</param>
+        /// <param name="currentSpecies">The current species</param>
+        /// <returns>True if the species can toggle Gigantamax potential</returns>
+        public static bool CanToggleGigantamax(this IGigantamax _, int currentSpecies)
+        {
+            var soup = CanEatMaxSoup;
+            return soup.Contains(currentSpecies);
+        }
+
+        private static readonly HashSet<int> CanEatMaxSoup = new HashSet<int>
+        {
+            (int)Species.Venusaur,
+            (int)Species.Charizard,
+            (int)Species.Blastoise,
+            (int)Species.Rillaboom,
+            (int)Species.Cinderace,
+            (int)Species.Inteleon,
+            (int)Species.Butterfree,
+            (int)Species.Pikachu,
+            (int)Species.Meowth,
+            (int)Species.Machamp,
+            (int)Species.Gengar,
+            (int)Species.Lapras,
+            (int)Species.Eevee,
+            (int)Species.Snorlax,
+            (int)Species.Garbodor,
+            (int)Species.Drednaw,
+            (int)Species.Corviknight,
+            (int)Species.Toxtricity,
+            (int)Species.Alcremie,
+            (int)Species.Duraludon,
+            (int)Species.Orbeetle,
+            (int)Species.Coalossal,
+            (int)Species.Sandaconda,
+            (int)Species.Grimmsnarl,
+            (int)Species.Flapple,
+            (int)Species.Appletun,
+            (int)Species.Hatterene,
+            (int)Species.Copperajah,
+            (int)Species.Kingler,
+            (int)Species.Centiskorch,
+            (int)Species.Urshifu
+        };
     }
 }