There are really only 4 viable solutions for a hard bricked Moto "letter" device, assuming this is truly hard bricked and not a battery or charging issue. Being hard bricked on one of these devices means that the bootloader is inaccessible and the device doesn't boot, if the bootloader is inaccessible we have few options remaining for self-repair.
Qualcomm HS-USB Qloader 9008 - All Qualcomm devices have the ability to be hard flashed with the proper files. Although this is an option for many devices, it is not for these devices because Moto/Lenovo will not release the necessary files. Thus this is not a valid option for these devices, I only bring this up because searching the internet will return many references to this tool, but we cannot use it thanks to Moto/Lenovo policy on these devices. - Source
JTAG programming - Requires an external device and ROM files, assuming the partitioning is still intact this is a viable option although for lower end or older devices, the price of the programmer is often significantly more than the value or replacement cost of the device, with modest units costing around $200USD (source) without the necessary cables which sometimes need to be purchased separately or fabricated, and the initial cost of this device when new was $100USD and it's current value is around $30USD, most likely makes this option undesirable.
Authorized Service Center - Have the device repaired by an authorized Moto service center. Due to the age of this device, it is likely out of warranty and the cost will likely be more than the device's value or replacement cost. I have no reference for this information, so it might be worth your time to investigate it yourself, if this was the result of an official OTA update, it may be possible to find a sympathetic ear at a local authorized repair center.
So this brings us to the Final Option... As noted in some of my previous options, the cost/value of the device needs to be considered here. The Moto E is a low-end, low cost device and was released in May 2014, just over 3 years ago. This device has very little value and a replacement unit would likely cost less than any valid repair option, so it may just be time to discard/recycle the device and purchase a new or used replacement device.
Like many things in life, not everything can be feasibly or economically repaired, sometimes you just have to accept that and move on.