I love Ohio questions.
For defense of property:
You must have a reasonable belief that your conduct is necessary to defend your property against the imminent use of unlawful force, and the force used is not likely to cause death or great bodily harm.
So, don't use gun, knife, baseball bat, or any other object on the other person. You can threaten more force than you can actually use.
If the person attacks you, then you get into self-defense.
You are entitled to use such force in self-defense as is proportional to the force being threatened. That force escalates up to lethal force.
To establish self-defense involving non-lethal force, the following elements must be shown: The defendant was not at fault in creating the situation giving rise to the fight. The defendant also must show that the defendant had an honest belief that he was in imminent danger of bodily harm, and that his only means of escape was by the use of force. The defendant must not have violated any duty to retreat to avoid danger. State v. Dietz, 2003 Ohio 3249 (8th Dist. App. 2003)
To establish self-defense in a lethal setting or where you use a weapon, "a defendant must prove * * * (1) that the defendant was not at fault in creating the situation giving rise to the affray; (2) that the defendant had a bona fide belief that he was in imminent danger of death or great bodily harm and that his only means of escape from such danger was in the use of such force; and (3) that the defendant did not violate any duty to retreat or avoid the danger." State v. Barnes (2002), 94 Ohio St.3d 21, 759 N.E.2d 1240 There is no duty to retreat from one's home. State v. Williford (1990), 49 Ohio St.3d 247, 551 N.E.2d 1279.
To answer your question, if the person attacks you, you can hit back to stop the attack. You can only use force while there is a threat, so continuing to beat someone on the ground is bad.
Might I suggest, rather than looking at self-defense, you instead look at a civil protection order keeping this person off of your property/away from you? Its easier to do, and then, if this dude comes on your property, the police can arrest them for violating the order.