Seira is a godSeira, the Student Council President, repeatedly demonstrates a superior knowledge of Kanade's situation, and knowledge that goes beyond what he knows or is able to learn. She even knows more than the Flippant God or his predecessor, as she actually knows what he needs to do in order to break the curse. Her flippant personality that plays with everyone like toys closely resembles the Flippant God as well. It certainly seems like she could legitimately be not only a deity, but the missing deity that created the curse.
WMG / Ore no Nounai Sentakushi ga, Gakuen Love Come o Zenryoku de Jama Shiteiru