Responses
In some rare cases, a person can be both a guide and an esper or in this case, a Sentinel. Colton seems to have both without realizing it. It's just that if that person with both uses their esper side, they will still need guiding from someone else. At least it seems the author wants Colton to be both as he provided guiding but on paper he's a Sentinel.

Correct me if I’ve got this right or not?
It’s a Guideverse AU. In this version, "Guides" are actually Sentinels—meaning they’re the ones with powers who do the fighting. Following the original story's dynamic, both Damon and Colton are Sentinels; however, unlike the original, Damon is an S-Class Vanguard Sentinel (the most powerful), while Colton is a normal A-Class Sentinel (lower rank). This flips the original dynamic where Colton was the dominant alpha and Damon the recessive one—at least for now.
What I don't understand is: if Colton is a Sentinel, how can he provide "guiding" to Damon? In this chapter, Damon used his powers so heavily he nearly reached corruption levels; Colton saved him by performing the guiding process—using his powers just as Damon asked. Damon ended up in a coma, but Colton didn't. Both were exposed to contamination, yet Colton tested negative—which is strange, considering he didn't fall into a coma like Damon. You'd expect his Sentinel class to make him *more* susceptible to the contamination levels found in the Fracture (which did affect him, since he suffered hallucinations and Damon had to save him). Also... can a Sentinel be a Guide at the same time? That’s the central plot of the story, right?