Consecration is a mod that makes all undead mobs more resilient except through fire and holy damage. To deal with this new obstacle, this mod also adds a few new items that help the player deal more fire and holy damage in the course of their adventure.
Undead mobs will be more resilient against most forms of damage. Undead mobs include all types of zombies, skeletons, and the Wither. This resilience comes in the form of damage reduction and health regeneration. The only way to depower the undead is to smite them, either through fire damage or holy damage. Fire damage will only work on undead mobs who are not already immune to fire, so it will not work on Nether mobs. Holy damage is a bit of a loose term, but this mod adds a couple ways of dealing holy damage.
The Fire Stick is a simple early-game tool that deals no additional damage to enemies but has the ability to set them on fire for 2 seconds, which is enough to depower the undead for a short time. Note that this tool is limited to 13 uses, so use it wisely.
The Fire Arrow is a simple early-game weapon that acts exactly the same as a normal arrow when shot except that it will set enemies on fire.
The Potion of Consecration is a divine potion brewed perfectly for killing the undead. Not only is this potion capable of depowering the undead, it also provides beneficial effects, proportional to the power of the potion, to anyone who drinks it.
In order to brew this potion, you need to first brew an Awkward Potion. Then, use a golden apple as a reagent. This will brew you the basic potion.
You can brew a more powerful version by using Glowstone Dust as a reagent afterwards.
Unless you can somehow make the undead drink this potion yourself, you're also going to want to make either the Splashing or Lingering version of this potion. The brewing recipe for these are the same as for all the other vanilla potions (gunpowder and dragon's breath, respectively).
Armor enchantment that reduces damage from undead attacks. Works like Protection enchantments, including not being able to stack with them except for Feather Falling.
Khioni - Fire Arrow and Fire Stick textures