In a large bowl, whisk together the tea and soy sauce. Add the garlic and onion. Add the chicken and cover with plastic wrap. Refrigerate at least 4 hours or up to overnight.
Preheat the oven to 425 degrees F.
Remove the chicken from the marinade and use a paper towel to pat dry. Sprinkle each side of the chicken generously with salt.
In a shallow dish or bowl, add the flour, paprika, garlic powder, onion powder, ½ teaspoon salt and ¼ teaspoon pepper.
Place the butter on a rimmed baking sheet or glass baking dish. Put it into the oven until melted, about 2 minutes.
Thoroughly coat each piece of chicken in the flour mixture. Place each chicken piece skin-side down in the melted butter. Bake for 30 minutes. Flip and bake until golden brown and crispy and the chicken registers 165 degrees F on a meat thermometer (avoiding bone), another 20 to 30 minutes. Serve with lemon, if desired.