Here's a simple rule: if you're over 18 and they're under 18, don't fuck 'em.
There, see? Simple, to the point, and holds true almost 100% of the time.
This is the one thing you don't want to overcomplicate with semantics, my guy.
You guys are arguing semantics here, it's absolutely not worth it. No one cares if it's "technically" ephebophilia, because this is a very emotional topic based on real people engaging in real-world activity, not some controlled scientific experiment, thesis paper, or legal document.
To the vast majority of the world, this guy is a pedophile as he's still preying on someone under the normally accepted (at least in the West) legal age of 18. Anyone under that age is very likely still in the care of their parents or legal guardian, and I STRONGLY doubt they would be okay with some grown-ass adult wanting to copulate with their child who isn't even old enough to vote (or in some cases, hasn't even entered puberty).
You can try arguing the semantics of this as much as you want but it's going to come with a lot of side-eyes considering on an emotional and societal level (as in, outside the realm of theory or legal definition), the absolute majority will see anyone who's an adult, trying to have sex with someone under 18, as a pedophile. And considering the typical perversity of people vying after those not of adult age, they have every right to be viewed that way.