FAQ[]
http://www.sjgames.com/gurps/faq/FAQ4-5.html#SS5.2.2
5.2.2. How do I build an Innate Attack which ignores all DR, even Hardened?
Buy the Innate Attack with the Cosmic (Irresistible Attack) +300% and Cosmic (Bend rules: ignores Hardened too) +50% enhancements. It will only be countered with Cosmic DR. In general, the GM should consider power tiers if such issues are common.
quotes[]
PK[]
2010 http://forums.sjgames.com/showpost.php?p=1022118&postcount=2
Insubstantiality does not let your attacks pass through armor. You need Cosmic for that. But you can limit Cosmic to bring its cost down (Limited Enhancements, p. B111). What you want is something like:
Toxic Attack (Affects Substantial, +40%; Cosmic, Irresistible Attack, Only vs. mundane armor, +270%; Melee Attack, Reach C, No Parry, -35%)
And remember that your wraith has to buy his Insubstantiality with the +100% Affects Insubstantial enhancement as well.