You wont be able to craft Ghostbane. Only Ghost Touch thru Cannith Crafting, or
Your choices would be to take feat or enhancement that grants the weapon(s) you're wielding Ghost Touch, such as the Epic Destiny Feat Holy Strike:
Holy Strike Passive Your weapons gain Ghost Touch. Your vorpal strikes deal 10d6 untyped damage vs. Evil enemies. (This bonus damage works with melee, unarmed, and ranged attacks.)
Number of Destinies: 1
Or a Ruby of Ghostbane augment if the weapon has a red augment slot.
EDIT ~ For Cannith Crafting find a weapon that you want to disjunct that has a red augment slot. I don't know if they exist, but for example purposes, you disjunct a silver weapon with a red augment slot.
I would then craft Holy Burst as the prefix and Greater Undead Bane as the suffix. Then I would slot a Ruby of Ghostbane into it for Ghost Touch.
From the Cannith Crafting Planner to make a bound version:
Highest Divine shard level is 92
Highest Any shard level is 45
Total Item Potential Required: 9 (Min Level on item will be 16)
You will have to make:
Shard of Greater Undead Bane
Shard of Holy Burst
Shard of Potential (+6 Maximum Enhancement)
Shard of Potential (+7 Maximum Enhancement)
Shard of Potential (+8 Maximum Enhancement)
Shard of Potential (+9 Maximum Enhancement)
The result would be a silver weapon that had Holy Burst and Greater Undead Bane on it that is Ghost Touched.
- Silver blank with red augment slot
- Prefix ~ Holy Burst, Deals 2d6 alignment damage on a successful hit, Critical hits deal an additional (Crit Multiplier +1)d6 alignment damage
- Suffix~Greater undead Bane, Against the listed type or subtype of creature, enhancement bonus is +4 better than normal and deals 3 to 18 extra damage.
- Ruby of Ghostbane for Ghost Touch (the 3-18 from the suffix will trump the augments 1-6 and don't stack)
EDIT ~ A Shard of Masterful Craftmanship will drop the min level to 14. Don't forget you may wish to increase the damage rating with Item Plus. This will increase the ML. If I add the Shard of Masterful Craftmanship and add +2, it will make the ML 18.