In a large bowl, mix 3 cups of the flour, garlic powder, onion powder, Cajun seasoning, seasoned salt, kosher salt, and pepper. While whisking, add the water to the bowl until the batter comes together. It should resemble a thick cake batter with no lumps. On a separate plate, mix together the remaining 1 cup of flour and a pinch of salt.
If using vegan chicken shreds, take a small handful (about ¼ cup) and lightly coat them in the batter until you can form a disk in between your palms. Place the disk on the plate with flour and gently coat.
Transfer the battered disk to a separate plate and repeat with the remaining chicken shreds. Refrigerate until firm enough to handle, about 15 minutes. If using vegan strips or drumsticks, coat each piece in the batter, roll in flour, and set aside.
Pour 3 inches of oil into a heavy skillet or Dutch oven. Heat the oil over medium high to 350°F, or when a little bit of batter slowly bubbles up when dropped into the pan. Line a plate with paper towels.
Working in batches, slip the battered vegan chicken into the oil and cook for 4 to 5 minutes, until golden brown and crispy. Drumsticks will take a bit longer, about 6 minutes. Drain the chicken on the paper towel–lined plate and add a sprinkle of salt. Repeat with the remaining chicken.
Serve immediately.