Can I use an Iphone as a Wi-Fi Reciver?

I have a friend who has an Iphone 6 and we want to game online with my computer… And my desktop sadly doesn't have a network card and the eithernet cable we were using got eaten by rats… Is it possible to use my friends Iphone 6 to connect to the Wi-Fi and basically act as a network card for my computer… Keep in mind I don't want to use any of his data

No sadly not. Just spend a few £/$ on an ethernet cable

If you "don't want to use any of his data" what is the point of using his iphone as a "network card"? If you just want to connect his computer to yours setup an "Ad-Hoc" wireless connection. Ad-Hoc Wi-Fi is simply computer to computer Wi-Fi no router no internet etc.
Thus you can game etc. All that is required is both machines have Wi-Fi adapters! How you setup Ad-Hoc depends on what operating system (Windows 7,8 10, Linux, Mac, etc) and since you didn't say what you use we can't help you much.
Now if you really intend to play games ON-LINE you will be using the iPhones data! Lots of data as well!

You question does leave lots of other questions!

If your dataplan supports tethering, then yes. Just be sure how much data you can use in a month!

Yes