Solution: Install a modchip on mariko/oled, and follow stehix's unbricking guide. You should be able to just boot into hekate and do it on an unpatched switch. The boot partition is corrupted. You should be able to keep your data in most cases if done properly.
Thanks for the guide! I replaced mine, but the front camera is now black and gives me a pop up saying the iPad needs to cool to reactivate flash. Any ideas? Faulty replacement?