How many seizures qualify an individual for a medical discharge?

First the Army will try to see what is wrong with you and try to patch up. The Army doesn't just discharge you and push you off to the VA. It may take a while but if they deem they can't return you to duty or reclass you into a another MOS then they will initiate a MED Board. That will take some time. Just try to get taken care. The first step is to find out what is going on. When you start the process then you can worry about it.

Had a Ranger Buddy that had seizures. They couldn't figure out what caused them so they MEBd him. Think he had 3 or 4 before they admitted defeat and started the MEB paperwork.

There isn't a number. When you are submitted for a MEB it is much more thorough than what you are describing. You will be evaluated and given a diagnosis. Once they know what your condition is the decision will be made if this is a preventable or treatable issue or if it is chronic. After you have a diagnosis and the Army better understands your case the choice will be made of whether or not to submit you to a board. You will be evaluated by the VA among other steps. Your package will be submitted and you will get a finding and percentage. If you are getting over 30% for the issue you will be medically retired. If you are deemed unfit for service but given a percentage under 30% you will be medically separated and given a severance package. You would also receive your VA percentage which is based off all of your issues and not just this situation causing the seizures. You are way too early in the process to make any guesstimations on what will happen.