If you're talking about the new iPad Pro, 2018 version, then yes you can charge your iPhone XS, and it should fast charge it as well. But you will need a USB-C to Lightning cable in order to do so.
If you're talking about the new iPad Pro, 2018 version, then yes you can charge your iPhone XS, and it should fast charge it as well. But you will need a USB-C to Lightning cable in order to do so.
I tried out an adapter I found. The USB-A to USB-C adapter is able to charge my iPhone normally, at about 5watts. To get fast charging speeds, I still need to use the USB-C to Lightning cable, to get to 18watts.