Father and I… don’t exactly see eye to eye anymore. Used to, but it’s been a long time.
Iblis is… well, Shaytan. He’s the devil. He’s made it his life’s work to lead as many human beings as possible to Hell, and he’s been doing it for thousands of years. He followed a similar trajectory to Lucifer, if a bit later, but is more direct. Lucifer went to Hell, Iblis walks the Earth until Judgment Day. He isn’t fighting a war against Heaven, because he knows he has already lost, he’s just working to make sure as many people as possible share in his misery, and those wretched humans get what’s coming to him.
Needless to say, he is arrogant, spiteful, and incredibly crafty. He isn’t interested in doing evil himself, just making sure humans do. He works through agents and intermediaries, sows discord across the world, and general fouls things up.
He’s also incredibly powerful. He managed to escape Solomon’s war unscathed, alone among the Djinn, and it has to be remembered that before his fall he was ranked near the angels. He can change his size, create illusions, and bend and twist reality in other subtle ways.