Minecraft version: 1.12.2
Wizardry version: 4.1.0

Issue details: While playing around, Apparently Wizards while they're doing their life drain spell to their victims: if you move far away enough from them the game freezes later resulting in a crash related to a Ticking Entity crash while the wizard were life draining other mobs.

Reproducing this crash through steps (This is best tested in creative mode cus it's faster):

1. Load a World, doesn't matter if it's existing or not.
2. Get the Wizard spawn eggs then spawn them. (Again, you can probably find them naturally spawning but this is faster)
3. Right click the Wizards with the Life Drain Spell Book so they can cast it. (You can find them spawning with the Life Drain spell but I Just do this to make sure)
4. Get any Hostile Mob Spawn Egg and spawn those. (I Usually go for slimes so you can reproduce the issue more easily)
5. Run or Fly Away from the Wizard while they're life draining the hostile mobs you've spawned.
6. The game will freeze shortly resulting it in saving the world and then crash the game.

Other mods involved: None, just this mod only.

Crash Report (Been cut down to the important bits):

---- Minecraft Crash Report ----
// This doesn't make any sense!

Time: 4/12/18 12:12 AM
Description: Ticking entity

java.lang.NullPointerException: Ticking entity
at electroblob.wizardry.spell.LifeDrain.cast(LifeDrain.java:75)
at electroblob.wizardry.WizardryEventHandler.onLivingUpdateEvent(WizardryEventHandler.java:324)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_25_WizardryEventHandler_onLivingUpdateEvent_LivingUpdateEvent.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:179)
at net.minecraftforge.common.ForgeHooks.onLivingUpdate(ForgeHooks.java:566)
at net.minecraft.entity.EntityLivingBase.func_70071_h_(EntityLivingBase.java:2086)
at net.minecraft.entity.EntityLiving.func_70071_h_(EntityLiving.java:295)
at net.minecraft.world.World.func_72866_a(World.java:1990)
at net.minecraft.world.World.func_72870_g(World.java:1952)
at net.minecraft.world.World.func_72939_s(World.java:1756)
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1845)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1096)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:397)
at net.minecraft.client.main.Main.main(SourceFile:123)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Thread: Client thread
Stacktrace:
at electroblob.wizardry.spell.LifeDrain.cast(LifeDrain.java:75)
at electroblob.wizardry.WizardryEventHandler.onLivingUpdateEvent(WizardryEventHandler.java:324)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_25_WizardryEventHandler_onLivingUpdateEvent_LivingUpdateEvent.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:179)
at net.minecraftforge.common.ForgeHooks.onLivingUpdate(ForgeHooks.java:566)
at net.minecraft.entity.EntityLivingBase.func_70071_h_(EntityLivingBase.java:2086)
at net.minecraft.entity.EntityLiving.func_70071_h_(EntityLiving.java:295)
at net.minecraft.world.World.func_72866_a(World.java:1990)
at net.minecraft.world.World.func_72870_g(World.java:1952)

-- Entity being ticked --
Details:
Entity Type: ebwizardry:wizard (electroblob.wizardry.entity.living.EntityWizard)
Entity ID: 113581
Entity Name: Wizard
Entity's Exact location: -174.28, 4.00, 271.04
Entity's Block location: World: (-175,4,271), Chunk: (at 1,0,15 in -11,16; contains blocks -176,0,256 to -161,255,271), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Entity's Momentum: 0.01, -0.07, 0.01
Entity's Passengers: []
Entity's Vehicle: ERROR NullPointerException: null
Stacktrace:
at net.minecraft.world.World.func_72939_s(World.java:1756)

Stacktrace:
at net.minecraft.client.multiplayer.WorldClient.func_72914_a(WorldClient.java:420)
at net.minecraft.client.Minecraft.func_71396_d(Minecraft.java:2737)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:418)
at net.minecraft.client.main.Main.main(SourceFile:123)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

Details:
FML: MCP 9.42 Powered by Forge 14.23.2.2654 5 mods loaded, 5 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored

| State     | ID         | Version      | Source                                         | Signature                                |
|:--------- |:---------- |:------------ |:---------------------------------------------- |:---------------------------------------- |
| UCHIJAAAA | minecraft  | 1.12.2       | minecraft.jar                                  | None                                     |
| UCHIJAAAA | mcp        | 9.42         | minecraft.jar                                  | None                                     |
| UCHIJAAAA | FML        | 8.0.99.99    | forge-1.12.2-14.23.2.2654.jar                  | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| UCHIJAAAA | forge      | 14.23.2.2654 | forge-1.12.2-14.23.2.2654.jar                  | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| UCHIJAAAA | ebwizardry | 4.1.0        | Electroblob's+Wizardry+-+4.1.0+-+MC+1.12.2.jar | None                                     |

Loaded coremods (and transformers): 
Launched Version: 1.12.2-forge1.12.2-14.23.2.2654
LWJGL: 2.9.4
GL Caps: Using GL 1.3 multitexturing.

Question for a workaround: Is disabling the Life Drain Spell also persist on wizards as well? Which means does it prevent them from using/casting Life Drain?