I don't know. He had it already, so I'm assuming he was enhanced by it. The films didn't tell us how the gems work exactly. In GOTG, Ronan seemed to be enhanced physically by the power stone, but he could also use it to destroy, like Thanos did with the Asgadian ship. However, when Thanos was fighting on Titan, Tony said that they had to stop Thanos from closing his hand so that he couldn't use IG, so I was confused by that, because you'd think he can just think of what he wants and just do it....I don't know. He's clearly strong in his basic form, because Ebony Maw said, "No other being has ever had the might to hold not one, but two Infinity stones", as he presented the space stone to Thanos. I just wish they had been more clear about what makes normal Thanos so dangerous or powerful since we only saw him in after credit scenes, yet everyone fears him, even Ebony Maw...who seemed pretty powerful.