It does look pretty bad to me, but I guess that's just what cats do. I'm able to keep them together for about 2-3 hours at this point and the chasing has decreased significantly. Today he got on top of her to try to groom her (The new kitten definitely likes the cat waaaayy more than the cat likes the kitten) and the kitten got a growl, smack, and stare down and he backed down for a while. The kitten is getting better at backing off and the older cat is getting better at ignoring him. Hopefully order will be established soon, so they can co-exist without my supervision.
If he's not already, it might be time to look into neutering him.
At that age, that probably isn't the issue. Even not neutered, that's a wee bit young for it. But yes, they can still do that. Sultans found that out with humans a LONG time ago...some of those eunuchs were perfectly capable. And a human male is far less likely to function than a cat, due to the psychological ramifications of lacking the...erm...bits. If a human can, a cat, who has no clue what those bits actually do, certainly can! Now, some say that it is all dominance, but I've seen neutered toms (gibs) quite happily wait in line for a willing queen. They do not, however, tend to wander the countryside, and are far less likely to fight over the matter.
