That's one heck of a commit you've got there...

I may have got a bit behind with version control. A lot behind, in fact. Maybe I'll go back and split this sometime - then again, I probably won't. But hey, at least it's here!

src/main/java/electroblob/wizardry/enchantment/EnchantmentMagicProtection.java

@@ -0,0 +1,111 @@
+package electroblob.wizardry.enchantment;
+
+import electroblob.wizardry.util.IElementalDamage;
+import electroblob.wizardry.util.MagicDamage;
+import net.minecraft.enchantment.Enchantment;
+import net.minecraft.enchantment.EnchantmentProtection;
+import net.minecraft.enchantment.EnumEnchantmentType;
+import net.minecraft.inventory.EntityEquipmentSlot;
+import net.minecraft.util.DamageSource;
+
+import java.util.function.Predicate;
+
+/**
+ * This class is for the various magic protection enchantments added by wizardry.
+ */
+// This was mostly copied from EnchantmentProtection, with the code cleaned up a lot (the vanilla one is awful java...)
+public class EnchantmentMagicProtection extends Enchantment {
+
+	/** The type of protection this enchantment gives. */
+	public final EnchantmentMagicProtection.Type protectionType;
+
+	public EnchantmentMagicProtection(Enchantment.Rarity rarity, EnchantmentMagicProtection.Type protectionType, EntityEquipmentSlot... slots){
+		super(rarity, EnumEnchantmentType.ARMOR, slots);
+		this.protectionType = protectionType;
+	}
+
+	// Who knew this was so complicated?
+	// https://minecraft.gamepedia.com/Tutorials/Enchantment_mechanics#How_enchantments_are_chosen
+	// https://minecraft.gamepedia.com/Enchanting/Levels <- This is what the results of the 2 methods below are compared to
+
+	@Override
+	public int getMinEnchantability(int enchantmentLevel){
+		return this.protectionType.getMinimalEnchantability() + (enchantmentLevel - 1) * this.protectionType.getEnchantIncreasePerLevel();
+	}
+
+	@Override
+	public int getMaxEnchantability(int enchantmentLevel){
+		return this.getMinEnchantability(enchantmentLevel) + this.protectionType.getEnchantIncreasePerLevel();
+	}
+
+	@Override
+	public int getMaxLevel(){
+		return 4;
+	}
+
+	@Override
+	public int calcModifierDamage(int level, DamageSource source){
+		if(source.canHarmInCreative()) return 0;
+		if(this.protectionType.protectsAgainst(source)) return this.protectionType.getProtectionMultiplier() * level;
+		return 0;
+	}
+
+	@Override
+	public String getName(){
+		return "enchantment.ebwizardry:" + this.protectionType.getTypeName() + "_protection";
+	}
+
+	@Override
+	public boolean canApplyTogether(Enchantment ench){
+		if(ench instanceof EnchantmentMagicProtection){
+			return false; // As per EnchantmentProtection, only feather falling can be applied with other protection types
+		}else if(ench instanceof EnchantmentProtection){
+			return ((EnchantmentProtection)ench).protectionType == EnchantmentProtection.Type.FALL;
+		}else{
+			return super.canApplyTogether(ench);
+		}
+	}
+
+	public enum Type {
+
+		MAGIC("magic", 1, 5, 8, s -> s instanceof IElementalDamage),
+		FROST("frost", 2, 10, 8, s -> s instanceof IElementalDamage && ((IElementalDamage)s).getType() == MagicDamage.DamageType.FROST),
+		SHOCK("shock", 2, 10, 8, s -> s instanceof IElementalDamage && ((IElementalDamage)s).getType() == MagicDamage.DamageType.SHOCK);
+		// Fire already exists, and the other types aren't used enough to be worth having
+
+		private final String typeName;
+		private final int minEnchantability;
+		private final int levelCost;
+		// What the heck was levelCostSpan for? Removed since it's never used.
+		private final Predicate<DamageSource> criteria;
+		private final int protectionMultiplier;
+
+		Type(String name, int protectionMultiplier, int minEnchantability, int perLevelEnchantability, Predicate<DamageSource> criteria){
+			this.typeName = name;
+			this.minEnchantability = minEnchantability;
+			this.levelCost = perLevelEnchantability;
+			this.criteria = criteria;
+			this.protectionMultiplier = protectionMultiplier;
+		}
+
+		public String getTypeName(){
+			return this.typeName;
+		}
+
+		public boolean protectsAgainst(DamageSource source){
+			return criteria.test(source);
+		}
+
+		public int getMinimalEnchantability(){
+			return this.minEnchantability;
+		}
+
+		public int getEnchantIncreasePerLevel(){
+			return this.levelCost;
+		}
+
+		public int getProtectionMultiplier(){
+			return protectionMultiplier;
+		}
+	}
+}

src/main/java/electroblob/wizardry/enchantment/Imbuement.java

@@ -1,12 +1,10 @@
 package electroblob.wizardry.enchantment;
 
-import java.util.Iterator;
-import java.util.Map;
-
 import com.google.common.collect.Iterables;
 import electroblob.wizardry.Wizardry;
 import electroblob.wizardry.registry.WizardryEnchantments;
 import electroblob.wizardry.spell.FreezingWeapon;
+import electroblob.wizardry.spell.ImbueWeapon;
 import net.minecraft.enchantment.Enchantment;
 import net.minecraft.enchantment.EnchantmentHelper;
 import net.minecraft.entity.EntityLivingBase;
@@ -15,7 +13,6 @@ import net.minecraft.entity.projectile.EntityArrow;
 import net.minecraft.init.Items;
 import net.minecraft.inventory.ContainerChest;
 import net.minecraft.inventory.Slot;
-import net.minecraft.item.ItemBow;
 import net.minecraft.item.ItemEnchantedBook;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTBase;
@@ -28,6 +25,8 @@ import net.minecraftforge.event.entity.player.PlayerContainerEvent;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 
+import java.util.Iterator;
+
 /**
  * Interface for temporary enchantments that last for a certain duration ('imbuements'). This interface allows
  * {@link EnchantmentMagicSword} and {@link EnchantmentTimed} to both be treated as instances of a single type, rather
@@ -59,8 +58,7 @@ public interface Imbuement {
 	/** Removes all imbuements from the given itemstack. */
 	static void removeImbuements(ItemStack stack){
 		if(stack.isItemEnchanted()){
-			// No need to check what enchantments the item has, since remove() does nothing if the element does not
-			// exist.
+			// No need to check what enchantments the item has, since remove() does nothing if the element does not exist
 			NBTTagList enchantmentList = stack.getItem() == Items.ENCHANTED_BOOK ?
 					ItemEnchantedBook.getEnchantments(stack) : stack.getEnchantmentTagList();
 			// Check all enchantments of the item
@@ -96,7 +94,7 @@ public interface Imbuement {
 						// If any imbuements were removed, inform about the removal of the enchantment(s), or
 						// delete the book entirely if there are none left.
 						if(enchantmentList.isEmpty()){
-							slot.putStack(ItemStack.EMPTY); // NOTE: Will need changing in 1.11
+							slot.putStack(ItemStack.EMPTY);
 							Wizardry.logger.info("Deleted enchanted book with illegal enchantments");
 						}else{
 							// Inform about enchantment removal
@@ -122,9 +120,9 @@ public interface Imbuement {
 
 				ItemStack bow = archer.getHeldItemMainhand();
 
-				if(!(bow.getItem() instanceof ItemBow)){
+				if(!ImbueWeapon.isBow(bow.getItem())){
 					bow = archer.getHeldItemOffhand();
-					if(!(bow.getItem() instanceof ItemBow)) return;
+					if(!ImbueWeapon.isBow(bow.getItem())) return;
 				}
 
 				// Taken directly from ItemBow, so it works exactly the same as the power enchantment.