Wow, he's pretty! Probably a half-moon tail, but he might be a rosetail--there's a lot of branching in his tail.
Can you get a picture of him flaring? Just show him a mirror or a picture of another betta. Or turn all the lights off in the room he's in except the tank light. Sometimes showing them colorful objects works as well. Mine flares at peacock feathers.
Hi, thank you both for your response! His name is Lucky Batman (like my screen name) because we liked the name Lucky and Batman for his coloring lol. He's sleeping right now so I don't want to disturb him but here is a pic from earlier on today that has better lighting! Sorry the pic got rotated weird!