Magic is tempting to all who use it. Magical objects are no less tempting. No matter what though, it comes with a cost. I had strong magic before the gauntlet, yes, very strong.
It was after I took it when I paid the ultimate price. I got more power, but I was also dying. No matter how many times I lost it, I got it back. No matter how many times I didn't want to, I used it.
Yes, it was the biggest mistake of my life, but I'm still alive aren't I, I still have my magic don't I? Looking at the hour glass I see I may not have either for long, but hey, why not use my magic while I've got it? Why not use my enemy? That's where Aladdin comes in.
I will transport my essence into his body and become Sultan, and by the time the 'good guys' figure it out I will already have control over the Seven Deserts. When it comes down to it, I guess the price wasn't too much.