Choonster

LivingUpdateEvent doesn't have a DamageSource source field (because it's not at all related to an Entity taking damage). You shouldn't need to manually remove the PotionEffect when it runs out, EntityLivingBase will do that automatically. If you want to react to and cancel damage received by an EntityLivingBase, subscribe to LivingHurtEvent instead.

Your preInit method has FMLInitializationEvent as its parameter instead of FMLPreInitializationEvent. This means it's still being called during init instead of preInit.

You can replace vanilla's block models with a resource pack.