Ifrit even appeared in bodily form during this battle, but it was for naught, and Rimuru withdrew Ifrit back into his body before moving on to other techniques.
Even when Rimuru became a True Demon Lord, he still had limited use for Ifrit.
Ifrit was a powerful and terrifying monster, impossible to control, and Shizue cried out in horror when Ifrit killed the only friend Shizue had at the time.