It sounds to me like the root cause is boredom.
Bengals have a reputation for being very high energy cats. Furthermore, at 9 months old, I would expect him to still have kitten levels of energy. So already I can tell he almost certainly requires a lot more play than the average cat. But also his pattern of behavior, sleep, chase, attack, follows the normal pattern for cats, which generally is sleep, hunt, eat, and sleep again. Right when he wakes up, that's surely when he'll be most ready to cause trouble.
Establish a routine, and tire him out.
If you get him on a steady routine, it'll be more predictable when he'll wake up and want playtime. Start by playing with him at a set time every day, and get him really tired out. Then, once he's tired out, give him his meal. Hopefully after he's done eating, he'll naturally want to sleep. You'll want to give him multiple meals a day this way to help establish the routine. Once he gets used to the schedule, hopefully his natural rhythm will start to fall at predictable times, and you'll know exactly when he needs to be tired out.
Bengal cats seem to really benefit from leash training, as the outdoors are a lot more interesting than inside, and it encourages them to work off energy simply by walking around, even if they're not in the mood for playing. If you're successful with getting him to accept the leash, then it would surely be beneficial to make walking him on a leash part of your routine. Of course, don't expect the cat to take to the leash immediately. You must very slowly introduce him to the leash, and reward him for accepting it using food or treats.
Look for other forms of entertainment.
- Windows. You can make them even more entertaining by setting up a birdfeeder just outside, and adding cat shelves and the like to make it easier to sit at.
- Exercise wheels. There are exercise wheels available for cats, and some cats seem to really take to them. It's not guaranteed the cat will want to use the exercise wheel on its own, but you can try to encourage him to use it with treats.
- Cat patios. Set up an enclosed pen in your yard to allow the cat to safely be outside.
Help your other cats avoid him.
Add alot of cat furniture around your house. Arrange it and your regular furniture to create higher routes for the cats all around your house. These routes should have multiple ways your cats can access them. That way, they can escape to the cat furniture in order to avoid your younger cat, and he cannot trap them by guarding the one route back down.