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/spell/ForestOfThorns.java

@@ -0,0 +1,99 @@
+package electroblob.wizardry.spell;
+
+import electroblob.wizardry.block.BlockThorns;
+import electroblob.wizardry.registry.WizardryBlocks;
+import electroblob.wizardry.registry.WizardryItems;
+import electroblob.wizardry.tileentity.TileEntityPlayerSaveTimed;
+import electroblob.wizardry.util.SpellModifiers;
+import electroblob.wizardry.util.WizardryUtilities;
+import net.minecraft.entity.EntityLiving;
+import net.minecraft.entity.EntityLivingBase;
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.item.EnumAction;
+import net.minecraft.tileentity.TileEntity;
+import net.minecraft.util.EnumFacing;
+import net.minecraft.util.EnumHand;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.world.World;
+
+import javax.annotation.Nullable;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ForestOfThorns extends Spell {
+
+	public ForestOfThorns(){
+		super("forest_of_thorns", EnumAction.BOW, false);
+		addProperties(EFFECT_RADIUS, DURATION, DAMAGE);
+	}
+
+	@Override public boolean requiresPacket(){ return false; }
+	@Override public boolean canBeCastByNPCs(){ return true; }
+	@Override public boolean canBeCastByDispensers(){ return true; }
+
+	@Override
+	public boolean cast(World world, EntityPlayer caster, EnumHand hand, int ticksInUse, SpellModifiers modifiers){
+		if(!summonThorns(world, caster, caster.getPosition(), modifiers)) return false;
+		this.playSound(world, caster, ticksInUse, -1, modifiers);
+		return true;
+	}
+
+	@Override
+	public boolean cast(World world, EntityLiving caster, EnumHand hand, int ticksInUse, EntityLivingBase target, SpellModifiers modifiers){
+		if(!summonThorns(world, caster, caster.getPosition(), modifiers)) return false;
+		this.playSound(world, caster, ticksInUse, -1, modifiers);
+		return true;
+	}
+
+	@Override
+	public boolean cast(World world, double x, double y, double z, EnumFacing direction, int ticksInUse, int duration, SpellModifiers modifiers){
+		if(!summonThorns(world, null, new BlockPos(x, y, z).offset(direction), modifiers)) return false;
+		this.playSound(world, x, y, z, ticksInUse, duration, modifiers);
+		return true;
+	}
+
+	private boolean summonThorns(World world, @Nullable EntityLivingBase caster, BlockPos origin, SpellModifiers modifiers){
+
+		if(!world.isRemote){
+
+			double radius = getProperty(EFFECT_RADIUS).doubleValue() * modifiers.get(WizardryItems.blast_upgrade);
+
+			List<BlockPos> ring = new ArrayList<>((int)(7 * radius)); // 7 is a bit more than 2 pi
+
+			for(int x = -(int)radius; x <= radius; x++){
+
+				for(int z = -(int)radius; z <= radius; z++){
+
+					double distance = MathHelper.sqrt(x*x + z*z);
+
+					if(distance > radius || distance < radius - 1.5) continue;
+
+					Integer y = WizardryUtilities.getNearestSurface(world, origin.add(x, 0, z), EnumFacing.UP, (int)radius, true, WizardryUtilities.SurfaceCriteria.BUILDABLE);
+					if(y != null) ring.add(new BlockPos(origin.getX() + x, y, origin.getZ() + z));
+				}
+			}
+
+			if(ring.isEmpty()) return false;
+
+			// Because we're always using EnumFacing.UP in the code above, we can be sure that pos is the block above the floor
+			for(BlockPos pos : ring){
+
+				((BlockThorns)WizardryBlocks.thorns).placeAt(world, pos, 3);
+
+				for(int i=0; i<2; i++){
+
+					TileEntity tileentity = world.getTileEntity(pos.up(i));
+
+					if(tileentity instanceof TileEntityPlayerSaveTimed){
+						((TileEntityPlayerSaveTimed)tileentity).setLifetime((int)(getProperty(DURATION).floatValue()
+								* modifiers.get(WizardryItems.duration_upgrade)));
+						if(caster != null) ((TileEntityPlayerSaveTimed)tileentity).setCaster(caster);
+					}
+				}
+			}
+		}
+
+		return true;
+	}
+}