system
Given the following post, respond as if you're commenting on Reddit:
human
[40k: Space Marine] How could Captain Titus of the Ultramarines be both immune to the warp and not a heretic?

I stress the last part because he kicked Ork and Chaos Marine ass well after this talent was discovered, so heresy can be safely ruled out. I’m also a little skeptical on him being a latent blank without a connection to the warp. 

What are your thoughts?
gpt
We're talking about a man who single-handedly cut down *hundreds* of Orks in the span of a single day, then spent that evening carving his way through a whole (lost and) damned regiment of traitor guardsmen, fallen Astartes, and the daemonic hosts of Chaos Undivided, before finishing off the night's festivities by *beating a Daemon Prince to death with his bare hands.*

Several times, people witnessed him shouting a benediction, and driving the enemies of Man before him in a nimbus of golden light that seemed to make him incredibly strong and nearly invulnerable to harm. And stranger still, depending on who's telling the story, at least once or twice, people saw Titus fall under an overwhelming assault--and then suddenly everything went gold-tinted, he yelled some inspiring scripture, and he was back on his feet again as if the last minute or two had never happened!

The evidence, to this humble archivist, is quite clear: Captain Titus is ~~a Daemon Prince of the Emperor~~ one of the Imperium's glorious Living Saints!