monk picked up by the foundation for being able to project his calm onto others while chanting
So… just a mind-affecting effect then? Or standard compulsion? If the latter… that might be tough to work with, since we have a lot of SCPs that are basically "force people to feel/act/think a certain way". There's a fairly long list of tagged with "compulsion". That said, maybe also take a look at this discussion on compulsion and addiction effects.
He feels to be in the Euclid classification but I am uncertain.
I would say Euclid, since he's physically just a human who still has regular human needs.
I don't really know about this since "guy that just calms people down" isn't much to work with. Have you taken a look at the humanoid writing guide, by chance? Do you have any context/backstory for the monk? How he figured out his chanting powers? His reaction to them?
For the typical "human with a power" premise, we'd need to see something unexpected or a new perspective on things. There are a lot of powered humanoid articles that get posted every week, and most don't make the cut because the audience has either seen those things before or they're not written well enough to be interesting.