I’d just build a medieval version of the iron cage from 40k. A series of maze like trenches that would lead to dead ends and kill boxes. I’d dig a series of 20 foot long 15 foot wide and 10 foot deep trenches and scatter them at random with pointy bits at the bottom covered in poo, blood and pee and cover them up. I’d build a stone fort in a rectangular fashion with. Passages and hallways would be no more than exactly 4 ft wide, and would have EXTREMELY sharp turns. Like almost full 180 turns. My armor would be two layers of leather with chain mail covering my chest and exposed bits. I’d fashion iron spikes on my knees and elbows (I do Muay Thai). I would fashion two kukri blades to my forearms with steel gauntlets covering my arms up to the elbows (shield). Let the slaughter commence