I bought a brand new unlocked 6a off of Amazon, and decided this was a good time to try out Graphene. I followed the installation instructions, and part way through flashing, the web installer threw a "Error: Array Buffer Allocation Failed".

At this point I wasn't able to re-flash through the web installer, so I attempted to reboot the phone through the graphene fastboot. I then received a “Your device is corrupt. It can’t be trusted and may not work properly” error, and now the phone is stuck with the charging symbol stuck on the screen and I can't seem to interact with it at all.

Is the phone bricked? Any help would be greatly appreciated.

It's not bricked, you just need to boot back into the bootloader and try again. That error means you ran out of memory. Make sure the device you are flashing from has sufficient memory (RAM) and don't have a lot of browser tabs or other programs open in the background.

Thank you, any idea on how to boot back into the bootloader? It seems like the phone is stuck on the charging symbol. I've tried holding the power button, the volume down button, and both at the same time, but with no response from the phone.

Had the exact thing happen when trying to install on a new 7 pro until it showed as corrupt.

Ended up flashing with the stock OS from Google and then trying again but this time, launched Chrome 'As Admin' and it worked. Good luck