MediaTek K80 is stuck , computer store tells me the firmware chip is corrupted
The kernel version 3.18.19 is correlative with Android 6.0.1 Marshmallow, which also correlates with Security Patch level. The ROM is built userdebug test-keys so this is most likely (ported) custom ROM.
Looking for baseband version there are lot of different 'brands' for several phones or tablets, which is unusual.
What they have in common these are low-budget devices running entry-level MT6580 processor with serial number 0123456789ABCDEF in fastboot mode.
Indeed this looks like a typical chinese clone device often with fake android version and/or fake hardware specs (see #40386).
Nevertheless factory reset will not have such negative impact, only cache + userdata partition is formatted which does not harm the firmware/ROM.
The best source for 'stock' ROM is your device itself. Do a read back with SP Flash Tool and create your own scatter file with WwR MTK

check that device has unlocked bootloader and/or adb root access in recovery mode. download platform-tools and enter recovery/bootloader mode with volume keys
in bootloader mode factory reset by formatting cache + userdata from fastboot
fastboot devices
fastboot oem unlock
fastboot format cache
fastboot format userdata


in recovery mode formatting cache + userdata from adb shell with mke2fs (where mmcblkp1p99 is placeholder for partition number of the block device)
adb devices
adb shell ls -l /dev/block/*/*/*/by-name
adb shell mke2fs -t ext4 /dev/block/mmcblkp1p99


Reboot your device and wait a long time. device is encrypted on first boot, that might take up to 15 minutes