Time to talk why I think Fugil could take this, I will mention Culexus abilities one by one and I'm going to mention what can Fugil do againts them:
Power Null, Statistics Reduction and Mind Hax: This is done by nulling supernatural powers, which Fugil mostly lacks, so it will barely affect him. Fugil has recieved things that can burn and break his mind, drive him into insanity, paralyze people from fear, make them forgethow to breath due to fear, agony beyond imagination, his blood boiling, and having his nerves tampered, and that's only the effect of a 10% Baptism, Fugil survived a 100% one, so the effect of the mind hax are kinda moot for him.
Invisibility, Intangibility and Soul Hax: The invisibility gets countered by Fugil senses, I already explained why some post before. The intangibility doesn't matter much, Fugil despite not having NPI, Culexus needs to shift back to reality to touch Fugil, so Fugil can perfectly predict and attack Culexus at that instant. To apply the soul hax Culexus needs to touch his opponent first, so Fugil has the range adventage with his sword.
Grenades: I highly doubt it will really work, because Fugil basically lacks supernatural powers he won't be affected that much and at beast he should lose conciuosness. Except that he resist being forcefully put into uncounciousness, aside from Self-Sustenance Type 3 that I think should help with that.
Anything else tha I missed?