So I managed to get into Windows with my HDDs showing. The Corsair K95 keyboard may have been the issue, whether partially or fully.
Before this issue, I had moved my PC, so the PSU was turned off.
I noticed when I turn on the PSU, the keyboard will light up right away, before even booting up the system. Normally, after a regular shutdown, the keyboard stays off until next boot.
After booting the system, startup would either hang or freeze in the UEFI BIOS, and the keyboard lights would freeze (animated by default).
I'm not sure if the BIOS was actually freezing as it may have just been keyboard/mouse not responding. Though that doesn't explain the frozen ROG logo on boot.
For now, I'm going to blame Corsair, but I'll post again if the issue is still present.