Fix some things that I missed

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/AbstractDelegatingSpell.java

@@ -52,6 +52,10 @@ public abstract class AbstractDelegatingSpell implements ProjectileSpell {
         return type;
     }
 
+    @Override
+    public SpellTraits getTraits() {
+        return getDelegates().stream().map(Spell::getTraits).reduce(SpellTraits.EMPTY, SpellTraits::union);
+    }
     @Override
     public UUID getUuid() {
         return uuid;
@@ -113,6 +117,7 @@ public abstract class AbstractDelegatingSpell implements ProjectileSpell {
     @Override
     public void toNBT(NbtCompound compound) {
         compound.putUuid("uuid", uuid);
+        saveDelegates(compound);
     }
 
     @Override
@@ -121,8 +126,13 @@ public abstract class AbstractDelegatingSpell implements ProjectileSpell {
         if (compound.contains("uuid")) {
             uuid = compound.getUuid("uuid");
         }
+        loadDelegates(compound);
     }
 
+    protected abstract void loadDelegates(NbtCompound compound);
+
+    protected abstract void saveDelegates(NbtCompound compound);
+
     private static boolean execute(Stream<Spell> spells, Function<Spell, Boolean> action) {
         return spells.reduce(false, (u, a) -> action.apply(a), (a, b) -> a || b);
     }

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/CompoundSpell.java

@@ -3,14 +3,12 @@ package com.minelittlepony.unicopia.ability.magic.spell;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
-import java.util.Objects;
 
 import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 
 import net.minecraft.nbt.NbtCompound;
 import net.minecraft.nbt.NbtElement;
-import net.minecraft.nbt.NbtList;
 
 public class CompoundSpell extends AbstractDelegatingSpell {
     private final List<Spell> spells = new ArrayList<>();
@@ -35,22 +33,15 @@ public class CompoundSpell extends AbstractDelegatingSpell {
     }
 
     @Override
-    public void toNBT(NbtCompound compound) {
+    protected void loadDelegates(NbtCompound compound) {
-        super.toNBT(compound);
+        spells.clear();
-        NbtList spells = new NbtList();
+        if (compound.contains("spells", NbtElement.LIST_TYPE)) {
-        this.spells.stream().map(Spell::writeNbt).forEach(spells::add);
+            spells.addAll(Spell.SERIALIZER.readAll(compound.getList("spells", NbtElement.COMPOUND_TYPE)).toList());
-        compound.put("spells", spells);
+        }
     }
 
     @Override
-    public void fromNBT(NbtCompound compound) {
+    protected void saveDelegates(NbtCompound compound) {
-        super.fromNBT(compound);
+        compound.put("spells", Spell.SERIALIZER.writeAll(spells));
-        spells.clear();
-        if (compound.contains("spells", NbtElement.LIST_TYPE)) {
-            spells.addAll(compound.getList("spells", NbtElement.COMPOUND_TYPE).stream()
-                .map(el -> Spell.readNbt((NbtCompound)el))
-                .filter(Objects::nonNull)
-                .toList());
-        }
     }
 }

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/PlaceableSpell.java

@@ -1,8 +1,6 @@
 package com.minelittlepony.unicopia.ability.magic.spell;
 
-import java.util.Collection;
+import java.util.*;
-import java.util.List;
-import java.util.Optional;
 
 import org.jetbrains.annotations.Nullable;
 
@@ -16,7 +14,7 @@ import com.minelittlepony.unicopia.particle.OrientedBillboardParticleEffect;
 import com.minelittlepony.unicopia.particle.ParticleHandle;
 import com.minelittlepony.unicopia.particle.UParticles;
 
-import net.minecraft.nbt.NbtCompound;
+import net.minecraft.nbt.*;
 import net.minecraft.util.Identifier;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.util.registry.Registry;
@@ -134,7 +132,7 @@ public class PlaceableSpell extends AbstractDelegatingSpell {
             compound.putString("dimension", dimension.getValue().toString());
         }
         compound.put("castEntity", castEntity.toNBT());
-        compound.put("spell", Spell.writeNbt(spell));
+
     }
 
     @Override
@@ -149,7 +147,17 @@ public class PlaceableSpell extends AbstractDelegatingSpell {
         if (compound.contains("castEntity")) {
             castEntity.fromNBT(compound.getCompound("castEntity"));
         }
-        spell = Spell.readNbt(compound.getCompound("spell"));
+
+    }
+
+    @Override
+    protected void loadDelegates(NbtCompound compound) {
+        spell = Spell.SERIALIZER.read(compound.getCompound("spell"));
+    }
+
+    @Override
+    protected void saveDelegates(NbtCompound compound) {
+        compound.put("spell", Spell.SERIALIZER.write(spell));
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/Spell.java

@@ -19,6 +19,7 @@ import net.minecraft.nbt.NbtCompound;
  * Interface for a magic spells
  */
 public interface Spell extends NbtSerialisable, Affine {
+    Serializer<Spell> SERIALIZER = Serializer.of(Spell::readNbt, Spell::writeNbt);
 
     /**
      * Returns the registered type of this spell.

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/ThrowableSpell.java

@@ -78,15 +78,13 @@ public final class ThrowableSpell extends AbstractDelegatingSpell {
     }
 
     @Override
-    public void toNBT(NbtCompound compound) {
+    protected void loadDelegates(NbtCompound compound) {
-        super.toNBT(compound);
+        spell = Spell.SERIALIZER.read(compound.getCompound("spell"));
-        compound.put("spell", Spell.writeNbt(spell));
     }
 
     @Override
-    public void fromNBT(NbtCompound compound) {
+    protected void saveDelegates(NbtCompound compound) {
-        super.fromNBT(compound);
+        compound.put("spell", Spell.SERIALIZER.write(spell));
-        spell = Spell.readNbt(compound.getCompound("spell"));
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/util/NbtSerialisable.java

@@ -1,11 +1,10 @@
 package com.minelittlepony.unicopia.util;
 
-import java.util.Optional;
+import java.util.*;
+import java.util.function.Function;
+import java.util.stream.Stream;
 
-import net.minecraft.nbt.NbtCompound;
+import net.minecraft.nbt.*;
-import net.minecraft.nbt.NbtDouble;
-import net.minecraft.nbt.NbtHelper;
-import net.minecraft.nbt.NbtList;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Vec3d;
 
@@ -49,4 +48,38 @@ public interface NbtSerialisable {
     static Optional<BlockPos> readBlockPos(String name, NbtCompound nbt) {
         return nbt.contains(name) ? Optional.ofNullable(NbtHelper.toBlockPos(nbt.getCompound(name))) : Optional.empty();
     }
+
+    interface Serializer<T> {
+        T read(NbtCompound compound);
+
+        NbtCompound write(T t);
+
+        default T read(NbtElement element) {
+            return read((NbtCompound)element);
+        }
+
+        default NbtList writeAll(Collection<T> ts) {
+            NbtList list = new NbtList();
+            ts.stream().map(this::write).forEach(list::add);
+            return list;
+        }
+
+        default Stream<T> readAll(NbtList list) {
+            return list.stream().map(this::read).filter(Objects::nonNull);
+        }
+
+        static <T> Serializer<T> of(Function<NbtCompound, T> read, Function<T, NbtCompound> write) {
+            return new Serializer<>() {
+                @Override
+                public T read(NbtCompound compound) {
+                    return read.apply(compound);
+                }
+
+                @Override
+                public NbtCompound write(T t) {
+                    return write.apply(t);
+                }
+            };
+        }
+    }
 }