iPhone 5s Blue Screen of Death (Water Damage)
After hours of testing many components, I think it's the battery at fault. Every battery has a processor inside of it which lets the iPhone know how much it's charged and handles other system-level battery stuff. The water must have majorly screwed up that processor and the battery itself, because I'll turn the iPhone on once and it'll read around 40% and it will work for 15 minutes straight, before I turn it off and then back on again. But then it'll either say something really low, like 12%, or really high, almost always in the 80%, but it will crash with the Blue Screen Of Death and restart itself. I put the battery from a family member's iPhone 5s in and it works, and no matter how many times I restart it, I get the actual charged percentage and no BSOD. I got this battery from iFixit, who I've had good luck with in the past.