Intro high-end gaming computer for my nephew

What will you be doing with this PC? Be as specific as possible, and include specific games or programs you will be using.

My nephew has been saving for a while and has decided to enter the PC gaming scene. He says that's he's going to be playing games ranging from AAA titles to stuff like Rocket League. He enjoys Minecraft so he will probably be getting into the modded Minecraft stuff (FTB Beyond). The heavier modpacks. He loves Call of Duty so he'll probably be playing the latest COD that comes out. Same goes for Battlefield. He wants an all around good computer that can run new games at high settings at 1080p.

What is your maximum budget before rebates/shipping/taxes?

$1600 but it can be stretched a bit further if needed.

When do you plan on building/buying the PC? Note: beyond a week or two from today means any build you receive will be out of date when you want to buy.

As soon as possible

What, exactly, do you need included in the budget? (Tower/OS/monitor/keyboard/mouse/etc)

Everything

Which country (and state/province) will you be purchasing the parts in? If you're in US, do you have access to a Microcenter location?

He lives in a rural area in Colorado so no microcenter.

If reusing any parts (including monitor(s)/keyboard/mouse/etc), what parts will you be reusing? Brands and models are appreciated.

No parts to reuse

Will you be overclocking? If yes, are you interested in overclocking right away, or down the line? CPU and/or GPU?

No overclocking

Are there any specific features or items you want/need in the build? (ex: SSD, large amount of storage or a RAID setup, CUDA or OpenCL support, etc) A small SSD for the OS would be nice but unnecessary. I completely forgot. He is going to need wifi capabilities because he doesn't have access to an ethernet port near his computer.

Do you have any specific case preferences (Size like ITX/microATX/mid-tower/full-tower, styles, colors, window or not, LED lighting, etc), or a particular color theme preference for the components?

Mid-tower. He doesn't want a full-tower but he will go smaller. A windowed case with some LEDs would be nice but it shouldn't be hard to set up and it is unnecessary. So if the budget doesn't allow it, then a plain case would work fine.

Do you need a copy of Windows included in the budget? If you do need one included, do you have a preference?

Yes. Just a regular copy of Windows 10 would be fine.

Extra info or particulars: Nothing as of now. If anybody needs any more information don't hesitate to ask.

EDIT I completely forgot about something key in the specific features. He needs wifi capabilites.